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-   -   another transom job in the works - (http://www.classicseacraft.com/community/showthread.php?t=15671)

oldbluesplayer 07-18-2005 06:12 PM

another transom job in the works -
 
after I got my 73 Seafari home, and started heavily reading thru this forum, I got more than a little nervous about wet transoms, and started really checking mine out.

The outboard mounting bolts appeared to be at best marginally bedded, that motor was installed 15 years ago, and where the Teleflex cable mounting bracket was thru bolted, 2 of the 4 bolts were loose, and there was no bedding in there at all.

I soundly tapped the whole transom, and was freaked to find a totally hollow thump just below the Teleflex mounting bracket. Great.. figured I've got complete disintegration right there.

Turns out wrong, but I'm started in now. I cut the outer skin off, a 'la Finster's, perhaps better view is same as Hammer's 20, that has the same shape single outboard transom notch - anyways, about 5 in. below where the teleflex was mounted, in the transom core, was a 5" hole, all the way thru the core, to the inner liner, and that had been holed, and patched from the inside, as well. this must have been something from the factory ?!?

Well, the wood was wet, but not rotten, but what the heck, so I kept going and removed the wood, and will rebuild it from the inner liner out.

I realize there is a lot of past threads on this, but a couple of questions -

1 - best way to dig out the wood at the bottom of the transom ?

2 - I'm planning to lay up the new transom with 1/2" ply sheets, probably with a single 1/4" piece of luan first, using that, trimmed, to compensate for the uneven areas around that funny plug mentioned above, and also where the glass deformed over the years at the engine bolt holes. Should I try to get this all in one lamination stage, or laminate a single layer at a time ? (will be all West System epoxy)

3 - how do folks recommend holding the sheets in place, and under how much pressure, while the lamination sets up ?

Any thoughts most welcome !

Bill

Capt Chuck 07-18-2005 07:01 PM

Re: another transom job in the works -
 
Quote:

in the transom core, was a 5" hole, all the way thru the core, to the inner liner, and that had been holed, and patched from the inside, as well. this must have been something from the factory ?!?


Factory? , Yes. This plug filled in the space that was used for the overflow of the Live Bait well offered on some models [img]/images/graemlins/wink.gif[/img]

It probably looked like this--------->

http://img.photobucket.com/albums/v355/hatidua/2.jpg

NoBones 07-19-2005 12:55 AM

Re: another transom job in the works -
 
My 70' 20SF has the live well in the transom as well.It works great. Just install a 4 inch water proof inspection port to close off when not in use. No sense in dragging that extra weight when not necessary. http://i7.photobucket.com/albums/y273/krn54/Picture021.jpg[/IMG][/image]

NoBones 07-19-2005 12:57 AM

Re: another transom job in the works -
 
Oops, No picture. [image]http://http://i7.photobucket.com/albums/y27...Picture021.jpg[/image]

FELLOW-SHIP 07-19-2005 11:02 AM

Re: another transom job in the works -
 
Ha Bill
I did my transom from the inside so I really don’t have a great suggestion on how to get the plywood out of the groove other than a hammer and chisel. When you do it from the inside you don’t have that 4-6” groove to contend with.
As for the lamination schedule I would do one layer at a time you could probably do two sheets of plywood in a day one in the morning and another in the afternoon. I also used the west system and really like the stuff. Follow their booklets on doing a transom it worked for me. As for the method to hold things together I used the glue and screw method. I drilled holes in the plywood and bolted things together I also used C clamps. After all the wood is in you can plug up the holes in the plywood before you re glass the outside I also used a peanut butter thickened epoxy and trawled it under all the edges of the hull between the plywood all around between the plywood lamination schedule. Don’t forget the beer you will need lots of it.
FellowShip [img]/images/graemlins/wink.gif[/img]

oldbluesplayer 07-19-2005 12:06 PM

that looks like the hole...
 
although on my 20' Seafari it was on the other side, and more in-between the stringers, and completely glassed off in the outer skin - not visible at all - but it sure gave off a hollow thump, like I said, right under the Teleflex thru bolts, had me convinced the transom core was disintegrating.

Fellow-ship - thanks for the input - follow-up questions:

- how much does high humidity affect the cure of resin - should I wait for dryer weather ?

- what did you use for filler to get the peanut butter paste consistency - 403? or ??

thanks again

Bill

FELLOW-SHIP 07-19-2005 05:26 PM

Re: that looks like the hole...
 
Ha Bill
Humidity will not cause any problems as all regarding the west system you just don’t want to get a water into the work in progress will turn the epoxy a milky looking mixture that could effect the adhesion to the wood. As for the #403 I really cant remember I think that was the # I read the properties on the canister and took the one that had very good bonding properties in it. If I can remember the 406 and 407 is the best for fairing compound.
FellowShip [img]/images/graemlins/smile.gif[/img]

Abe's Rocket 07-19-2005 05:59 PM

Re: that looks like the hole...
 
i think it is #403 that make the peanut buttah

captj2 07-19-2005 06:38 PM

Re: another transom job in the works -
 
I replaced my transom from the outside leaving the inside f/g face in place. The wood was wet for the most part and a hammer and chisel worked pretty well but I also used a side grinder to make a square pattern of deep grooves in the wood. This made the chisel more effective and broke the work up into manageable sections. The grinder, carefully used,can clean most of the wood from the remaining f/g face and the transom edges,leaving a good surface to adhere the new wood.I used 2 sheets of 3/4" marine plywood. Whatever plywood schedule you use,dry fit each layer first to check your clamp setup.
Good luck.

oldbluesplayer 07-20-2005 12:52 PM

good input, guys - making progress-
 
went at it last night - got a 1" spade drill for the power drill and drilled out as much as I could, then went at it with hammer and chisel - got it about 3/4 done, should finish that tonight.

It's time for pictures - have to get some tonight, and get them downloaded for y'all

Rather than through bolting the layup, I'm letting my engineer mind wander a bit, as I do the cleanup, thinking about rigging a hinged press - clamp a bar at the top of the transom, a couple horizontal 2x4 arms rotating on that, extending out, and then some hinged arms down to the transom area, with cross braces to go up against the transom layers as I install them, then hang some weight off the end of the horizontal arms, get some mechanical advantage multiplying the weight and applying inward force to the pieces as I do the layup - if I do it I'll shoot some pix.

Bill

stoney 07-26-2005 09:19 AM

Re: good input, guys - making progress-
 
Here's how I pulled the reinforcing up to the transom.
Beware, keep the transom flat!
http://i15.photobucket.com/albums/a3...repair5_15.jpg

oldbluesplayer 07-26-2005 11:46 AM

Progress report -
 
might as well run thru a string of photo's -

boat as seen / purchased - very oxidized hull
http://i12.photobucket.com/albums/a2.../Sea_Craft.jpg

after getting it home, I spent a weekend wet sanding with 600 grit, then again with 1500 grit, then compounding and buffing, then waxing and buffing - cleaned up pretty well
http://i12.photobucket.com/albums/a2...-hullclean.jpg

however, the two hour tow home took it's toll on the transom - what appeared in the yard to be sound, with a minor crack inside the splash well, was significantly worse by the time I got home, cracked inside and out - and reading thru CSC back threads made me decide to pull the motor and start looking closer -
http://i12.photobucket.com/albums/a2...nsomcracks.jpg

so - a serious crack in the left lower corner of the outboard notch, and a really wet transom, time to go to work
http://i12.photobucket.com/albums/a2...r/worktent.jpg

decided to go in from the back / outside
http://i12.photobucket.com/albums/a2...omstripped.jpg

the cracks and soft core induced deformation left me with an inside skin which was not flat, so went to work on that first
http://i12.photobucket.com/albums/a2...gthecracks.jpg

(now, I don't know how many pix I can stuff in one entry - so we'll stop here for the moment -

Bill

oldbluesplayer 07-26-2005 12:09 PM

Progress report 2
 
moving right along - used the last seen clamps and block, wrapped in wax paper, to hold several layers of cloth/resin in place inside the transom upper lip, flattening and reinforcing that area, while at the same time putting a plywood reinforcement plate on the inside surface of the inner transom, in the area of the lower motor mount bolts, also pulling that area flat, results as seen
http://i12.photobucket.com/albums/a2...ksrepaired.jpg

this effort successfully pulled the inner transom wall flat, so that I could beginning shaping plywood plates for the transom replacement. In the original transom, between the outer skin and the face of the plywood, was a very heavy, and highly troweled / grooved layer of putty - the outer skin was not uniformly bonded to the core, and this also made for an offbeat thickness, so my transom layup looks to be 3/4" / 1/2" / 1/2" - I have the first two plates in now -
http://i12.photobucket.com/albums/a2...nsomplates.jpg

last night, after a good 24 hours cure, I pulled the bracing off, and checked thru the bolt holes, and a couple of taped off interior inspection holes, and I have a good solid mate and bond all the way across the transom.

and right now, I'm bushed - gonna take a break for a few days.

Added to the punch list:

the gas tank appears to have slid backwards during the tow home, stopping against the bolt / bracket in the keel for a thru hull transducer - that needs help.

the gas fill line looks ancient (well, 32 years old !) so some plumbing is in order.

I'm going to add a knee brace from the keel up to the transom.

I like the accessability I created with the hole in the splash well, so I want to dress that up for keeps.


Yes, I still think I'll get this in the water this season, yet....

I hope !!!

Bill

oldbluesplayer 08-01-2005 01:16 PM

next progress report -
 
but no pix till this evening -

the third plywood plate is now installed, another 1/2", bringing the installed transom thickness out to 1-5/8".

I spent about 4 hours yesterday, in between the showers, grinding the inside surface of the transom outer skin smooth, getting rid of all the original lumpy, grooved, and highly fractured putty layer that had been between the outer skin and the original plywood transom core.

The gas tank had come free, and had slid backwards about 2", stopping against the thru hull transducer mounting bolt, which come up thru ( !!!) the keel stringer, so I'm also plotting how to reinforce the keel stringer and fill the 5/8" thru bolt hole left from the old transducer, now removed.

Like working with the West System epoxy - running the 105 epoxy with 206 slow hardner, and 403 filler for paste batches; plenty of working time.

Anyone who does this, plan on plenty of measure twice, cut once, and trial fit, again and again. It seems to take hours of prep work, and getting all the little details ready, before starting the 30 minute rush of mixing epoxy and installing a part, and getting it clamped in place, but the quality of the result is directly dependant on the prep work.

It's getting there.... slowly.

Bill

oldbluesplayer 08-02-2005 02:14 AM

and some pix -
 
first - this ought to be lesson number 1 in how Not to install a thru hull transducer...
http://i12.photobucket.com/albums/a2...r/000_0289.jpg

next, the ground down rear transom skin... 4 hours worth of grinding dust everywhere !!
http://i12.photobucket.com/albums/a2...r/000_0288.jpg

and a shot of the transome with all three layers of plywood now bonded in -
http://i12.photobucket.com/albums/a2...r/000_0287.jpg

tonight I started patching the keel stringer / transducer hole - starting with plywood plates bonded on each side with epoxy/RW, tabbed out to the sides, then I'll plug the hole with thickened epoxy, then add a layer of RW over the whole works, again tabbed out to the sides, farther than the first layer.

progress, slowly.

Bill

BigMike8o9 08-02-2005 12:57 PM

Re: and some pix -
 
Wow thanks for such great detail and photos. I'm going to check out my transom when I pull the motor off for rebuilding and I was worried if I had such a repair ahead.
Definately going to store this thread in favorites.
What is the best way to check for rot. I normaly drill small hole to see if the wood is solid. I also inject west after wards because of its anti fungal tendency.
My wife says west system is my windex ( my big fat greek wedding is her faverate movie)one time I used it to glue a big cut closed, just to piss her off. I know that was bad...

oldbluesplayer 08-02-2005 03:31 PM

thanks - this website is great
 
and gave me a lot of guidance and inspiration to tackle this job - I had built surboards years ago, and was used to working with fiberglass, polyester resin, which kicks so hard and so fast compared to the West Systems stuff, so that didn't scare me off, but - doing a transom... I think I read every thread on this site, and over at classic-mako, that I could find, along with the West Systems book... also, my brother took a 23 Seabird, a couple years ago, and pulled the I/O out, filled and reinforced the transom, added a bracket, and mounted a 225 OB, so I had a little direct hands on experience to refer with.

best way to check wetness is undoubtedly with one of the meters - completely non-invasive - but if you're pulling the motor off the transom anyways, check the bolt holes out - how well were those bolts bedded, how long were they in there, was the boat moored in the water all season, or did it sit on a trailer between uses. If there is an aluminum trim piece in the transom notch, see if you can pull that off (mine came easy - others reported great difficulty) and check the fit between the transom outer skin and the motorwell cap - mine was sloppy - 1/8" - another source of water entry into the core.

More to come, but taking tonight off to go out with my girlfriend.

Bill

ScottM 08-02-2005 04:08 PM

Re: thanks - this website is great
 
Quote:

also, my brother took a 23 Seabird, a couple years ago, and pulled the I/O out, filled and reinforced the transom, added a bracket, and mounted a 225 OB, so I had a little direct hands on experience to refer with.

Bill,
Does he still have the Seabird? I've got a '72 that was converted from I/O to notched transom OB.

oldbluesplayer 08-02-2005 06:19 PM

re the SeaBird - oh yeah -
 
my bro definitely still has that - he keeps it out on the Vineyard, if you ever are off Oak Bluffs you might see it - "Bad Boy", probably with 4 or 5 guys fishin out of it !

It was originally a cuddy cabin, but he pulled the forward cap off, and converted it to a CC, had an old and problematic Mercruiser, pre-Alpha series outdrive, which after several years of headache went away, in favor of the OB on the bracket - he picked up an Armstrong bracket for cheap.

It moves !!

Bill

ScottM 08-02-2005 08:13 PM

Re: re the SeaBird - oh yeah -
 
Bill,
Where on the Vineyard? I fish the Derby every year and stay at a house in Oak Bluffs.

warthog5 08-03-2005 10:41 AM

Re: re the SeaBird - oh yeah -
 
Well, I gott'a ask.

oldbluesplayer, Why did you just cut the center of the core out? Rather than do a "Complete" transom rebuild.

IMHO You have set up two more point's that could result in a sheering motion, unstead of moving the forces all the way out to the side's of the boat.
You were already 80% there and fell short.

FELLOW-SHIP 08-03-2005 11:53 AM

Re: another transom job in the works -
 
Ha Worthog
Thanks for asking that question I thought the same thing but did not have the chance to post your question.

Ha Old Blues Player
I have to admit that I totally agree with your comments regarding the west system epoxy. I could never have done my boat all alone with out any help by using polyester resen. When I did my boat the first project I did was to laminate a layer of glass on the gas tank plywood deck in the shade here in South Florida after that “should have been easy project” I knew I needed more time that polyester would give me. If I can remember correctly I used 12 gallons of epoxy to do everything needed and don’t regret that decision as all.
FellowShip [img]/images/graemlins/grin.gif[/img]

oldbluesplayer 08-03-2005 02:44 PM

Good questions - some thoughts/ answers
 
Scott - my brother has a place in Oak Bluffs, back up by the water tower, Bad Boy is kept on a trailer at his friends, who is the owner of the Admiral BenBow Inn, down by OB harbor... by derby I assume you mean the striper/bluefish derby in sept ? We were there last year, expect to be there weekends again this year.

Fellowship - used to do the surfboard thing outside - shaping the foam is wicked dusty, and counted on a hard 10 minute clock on the polyester resin, from first hardener to useless - beginning to gel, in the summer in New England. Sure can't be any easier in Florida !

Warthog - You got the real question, which really bugged me as I started into this. I've been an engineer too long, so I analyzed the heck out of this, and every example I could find in the back pages and photo albums...

accumulated thoughts

finished strength will be a combination of bonded surface area and mechanical capture, both of transom and bracing structure - the inner well is a significant strengthening member, some of the inner well cuts I've seen worry me about weaking of the supporting structure

IMHO - look at TimD's pictures of a 20 rebuild - I would worry having taken the cutout that close to the edge of the transom, would really have to wrap the rebuild around the corner - tricky job, it appears that his CC had a double motor wide cutout, less side wing surface bond area, really needed to go full width, and evidently his wood was all shot

alot of the examples are on 23's, with a double wide motor cutaway, again, less surface area to bond to

closest to mine appeared to be Hammer's 20, same size boat, same transom shape with single motor cutaway - he appears to have done about the same shape cut out, plus, as I intend, he did a glass wrap from the inner transom / splash well, over the transom edge, and on to the outer face of the transom - excellant mechanical capture, plus it seals the one probably worst seam on the boat, preventing a reoccurance of water getting in to the new transom, and strongly reinforces the structure, between the primary structure, the transom, and the secondary supporting structure, the inner cap/splash well assembly - IMHO that inner cap/splashwell piece significantly supports the transom.

most everybodies pix showed a live well port on the port side of the motorwell, mine had a buried hole thru the core, on the starboard side, glassed over on the inside, glassed over on the outside skin, but a 4" hole thru the plywood core -

This feature alone completely fooled me - as it was directly below the Teleflex mounting holes, leading me to believe the core was disintegrated rotten.

I set the circular saw to 1/4" depth, and cut off the skin in the shape as seen, and aside from being wet in the motorwell/ motor mount hole areas, my plywood was intact.

If I thought plywood could adequately dry out, I might well have left it in place, but I know it can't adequately, in reasonable time, dry across the ply boundaries. Wet, up here in New Hampshire, even salt water will freeze in the winter, and the wet wood would eventually turn to mush from freezing and thawing.

I was initially prepared to have to cut more off, go all the way out to the edge, leaving a 3" rim, if need be, but I had good wood where I stopped.

Wow - this is Way Too Long - give you an idea about how much I researched and thought about this.

- I've got all good wood now
- I reinforced the inner transom
- I kept my supporting structure intact
- I'm going to tie the transom to the existing supporting structure, the splashell assembly, with a transom wrap
- I'm going to add a knee brace, supporting the transom to the hull floor/ keel stringer
- I'm being as careful as I can with all the surface prep work

and I'm gonna hope this works - and believe from all your previous efforts, that one can successfully cut holes in boats, and rebuild them satisfactorily !!!!

Bill

ScottM 08-03-2005 03:21 PM

Re: Good questions - some thoughts/ answers
 
Bill,
Yup, the striped bass/bluefish derby. We stay at a house up behind the Oceanview Restaurant on Laurel Ave. I'll be down there Sept 10-18 so maybe we can hook up some time?

oldbluesplayer 08-03-2005 03:59 PM

Scott -
 
cool - I'll probably be down there several weekends in Sept - we launch the Bad Boy on the town ramp over in the lagoon by Vineyardhaven - definitely have to hook up -

right now I'm estimating one more weekend, good weather permitting, to finish my boat up, then give it a trial splash in a local lake, then a more serious shakedown up in Winnpesaukee, so's I can chase some salmon while I'm at it... and swim to shore if it falls apart... -:) and then hopefully get out to the coast for some blues - and if everything looks good, tow it to Falmouth and bop over to the Vineyard sometime during the derby.

Bill

oldbluesplayer 08-03-2005 04:20 PM

transom loads - Warthog -
 
looking further, I think I know where you are coming from, that most of the motor force forward thrust load is carried by the transom at the edges, into the hull - kind of similar, in reverse, to the transom test people talk about, standing on the tilted motor to see if the transom flexes under the weight -

both views are expecting that the transom is an unsupported, or marginally supported, span, attached primarily at the ends, kind of like a simple bridge, except that the transom is also attached to the hull bottom, so it is more of an oil can flex - imagine cutting half of the top out of a 55 gal oil drum, then grip the edge, in the center - it would move up and down - any unsupported edge would do that -

It seems that cracks primarilary start to appear at the lower corners of the transom motor well cutout - leading me to suspect that most transoms are not adequately reinforced by inherent design, so that as soon as the core wood gets wet and begins to lose it's stiffness, the load is shifted into the glass, which if not overbuilt, soon begins to fail under the increased load - thus the cracks forming.

Imagine a straight line, width of the transom, fastened only at the ends. From underneath the line, you have a force, up against the line - now add - above the line, imagine a structure in the letter "W" sitting on the line, above it, in the center - the two bottom points of the W are on the transom line, the two upper points of the W are fastened to the boat hull - either directly or indirectly thru the cap -

the more strength in that center support, the better off the whole transom structure will be.

just my humble 2 cents worth.

Bill

strick 08-04-2005 04:24 AM

Re: another transom job in the works -
 
Bill you are putting me to sleep with all that darn engineer talk [img]/images/graemlins/grin.gif[/img] Just put it back together and I'm sure it will be fine....A buddy of mine is a structural engineer and a while back I asked him how I should go about testing an engine bracket that I built. His reply was bolt it to a wall and then put double the weight you anticipate it to bear and then jump up and down on it for a while and if it does not crack then you will be ok. This guy was on the discovery channel for some engineer competition thing and his team won [img]/images/graemlins/shocked.gif[/img] I like your boat and hope to find one like it some day over here on the left coast. Good luck.

strick

warthog5 08-04-2005 04:16 PM

Re: another transom job in the works -
 
HeHe I have a friend Robert Sebring that own's Dawson Boat's here in Pensacola. http://www.rlsebring.com/

He had made some test panel's and sent them to Pensacola Testing lab. The panel's were cored with 3/4in Nidacore.

They came back and said XYZ strength, bla,bla,bla. Robert said wait a min. Give it to me in layman's term's. Can 30 people stand on top of this hardtop?

They said 300 people can stand on it. [img]/images/graemlins/shocked.gif[/img] [img]/images/graemlins/crazy.gif[/img] [img]/images/graemlins/grin.gif[/img]

This was not on a center console [img]/images/graemlins/crazy.gif[/img]

oldbluesplayer 08-05-2005 01:27 AM

back to work - the inside story
 
ok - so last we saw, the keel had a hole in it, and I wanted to brace the transom with a knee, to stiffen and prevent any further cracks from developing in the splashwell, or transom corners - as seen
http://i12.photobucket.com/albums/a2...r/000_0276.jpg

so tonight I crawled underneath, ground off the gel coat around the transducer hole, and beveled the hole out a little - I had already slabbed a couple pieces of 3/4 ply on each side with RW and thickened epoxy

here is the partially filled keel hole, and the knee brace
http://i12.photobucket.com/albums/a2.../Kneebrace.jpg

and here is another shot of the knee - it's two shorter pieces of 3/4 ply bonded to one longer one, which is slabbed onto the side of the keel, again with epoxy soaked RW and filled epoxy butter
http://i12.photobucket.com/albums/a2...kneetokeel.jpg

I ran the knee up to the top of the inside transom stiffener plate, both of which end right below where the splashwell comes up to the transom
http://i12.photobucket.com/albums/a2.../topofknee.jpg

Tomorrow night I'll go back and tab the knee into both the keel and the transom support plate. Then I should be positioned to put the outer skin back on this weekend.

Bill

oldbluesplayer 08-08-2005 01:58 AM

the skin goes in -
 
sun night - took all weekend - maybe I'm just anal about details and prep - oh well.

a running picture story -
Sat morning
http://i12.photobucket.com/albums/a2...ayer/satam.jpg
pull off the cover and get ready to work
http://i12.photobucket.com/albums/a2...thenewcore.jpg

set up the work bench - I like 3M blue painters tape and wax paper - an easily renewable work surface
http://i12.photobucket.com/albums/a2...yworktable.jpg

first real job, cap the new transom with several layers of cloth / epoxy resin, using some quickie molds to help hold the shape
http://i12.photobucket.com/albums/a2...transomcap.jpg

now pull the molds off after that cured, and do a little sanding
http://i12.photobucket.com/albums/a2...pedtransom.jpg

now to start prepping the outer transom skin - I had previously ground clean the inside surface, but still needed to do the outside surface
http://i12.photobucket.com/albums/a2.../skinprep1.jpg

and then grind back the edges, both on the skin, and on the boat, so it would be ready to tape the seam after installation
http://i12.photobucket.com/albums/a2.../skinprep2.jpg

and then trial fit - it came out of that hole - would it go back in ?
http://i12.photobucket.com/albums/a2...kinfitting.jpg

mixed up more sauce, backed up the skin with a piece of RW, wet the core, skin and RW out, and installed
http://i12.photobucket.com/albums/a2...kinbonding.jpg

Halleluja !! the Skin is In !!!
http://i12.photobucket.com/albums/a2...heskinisin.jpg


word to the wise - this is a butt busting, dirty job - don't undertake this lightly.

On the flip side, rap the new transom with a hammer and hear the sharp, distinct sound of SOLID .... I like it !!!

Bill

strick 08-09-2005 02:53 AM

Re: another transom job in the works -
 
Looking good Bill. Keep those pics coming along.


Strick

Briguy 08-09-2005 01:54 PM

Re: another transom job in the works -
 
Great looking project! The easy part is over. Now the fairing and sanding come. Get yourself a good mask and goggle combination along with something to cover your body. IE old clothes or a body suit. A beer never tastes better than after a few hours of sanding in 90 degree heat.

Ed 08-09-2005 09:17 PM

Re: another transom job in the works -
 
Congratulations on finishing up your transom.

I am not trying to rain on your parade....However, I think I would it is very important to point out to others who may lack boat building or boat repair knowledge that this IS NOT the way most professionals rebuild transoms. The most accepted way amongst the boat building community is to remove the rear section of the liner, remove rotten core material, recore transom in one solid piece from the inside, and then reglass in the liner back in place.

Cosmetically, it is the most invasive method. Structurally it is the best method and of course, as with most things done right...it is the most time consuming method.

oldbluesplayer 08-10-2005 01:29 PM

oh well...
 
I wish it was finished - but at least it's getting closer.

I taped the seam last night, and finally got around to tabbing the knee and the keel hole repair. Off to see my girlfriend next, and get to the filling and fairing this weekend.

Ed - I hear where you're coming from, But....

"most pro's" ... ahem, excuse me while I clear my throat

see that hole in the keel stringer? the one where the drill slid off to the side, and didn't go straight thru the keel, but down the side, cutting all the way down thru the RW keel wrap. Done by a "Pro" boat yard.

I've read thru every string on this and other boards, rotdoctor, etc

Go back to currently page 91 of this site, poster Rich started a similar project, see thread "Wet transom Too" poster "Whitehawk" comes in and says the same thing you just did, then poster "Hermco" whom I believe is also a pro, come along and disagrees, that the external repair is also correct.

Sounds like this is an endless debate.

I'm an engineer, and I make up my own mind, based on what I see. I am not impressed with the transom design as found in this boat, in terms of structural support. It relied heavily on the integrity of the core, with inadequate supporting structure, provided, not with knees, or multiple stringers at full height coming right up to the transom, as seen in the mako's, but strictly thru the cap assembly. These boats have real nice stringers in the hull bottom, but, at least in mine, they reduce in height significantly before joining the transom, reducing their support value. The outer skin was 1/8" matt, rather suprisingly thin, with a thick layer of putty, heavily troweled and grooved, between that and the plywood core, while the inner transom was a combination of matt and RW - more meat in that. Wet plywood has the structural integrity of cardboard. If the core gets wet, it's all up to the glass, and the design... and then "pro" boat yards that drill holes thru the transom for bolts to mount things, and don't put any bedding in.

Ehh, what's the use, it's an endless debate, with as many variables as there are boat designs, and boat yards doing setups and repairs.

each one is a seperate case, in my eyes.

We'll have to hoist a beer together sometime - getting them in the water, and having fun, safely, is what it's all about.

Bill

BigMike8o9 08-10-2005 09:23 PM

Re: oh well...
 
Sorry Ed, I agree with Oldbluesplayer. The improvements are substansual. I once rebuilt a couple of ribs in an old ketch that was made in Formosa. Every body said that by not replaceing the rib and only forming a new one in it's place while still afloat that I was making the boat weak.
About a year and a half latter a drunck ramed the boat about three feet away from the repaires. The two ribs I made were the only undamaged in the cockpit area on both sides.Some of the stips lamenated were end to end and were gusseted to the keel.
The same here, O's repaire is a stronger then original improvement. I beleave that a future rot problem is also less likely. The stringers are not likely to go any faster then the outside of the hull and the motor pressure is now in a better method of transfer.
The transom will take less strain.

oldbluesplayer 08-12-2005 11:39 AM

a little more progress...
 
after bonding the outer skin, I have cleaned that up, sanded down the squeeze out, and done some seam taping
http://i12.photobucket.com/albums/a2...pedtransom.jpg

also went back inside and finished up the transducer / hole in the keel repair, and tabbed in the knee

here is the foot of the knee, showing how it is 3 layers of ply thick, and bonded to both the side, and the top, of the keel - also the finished transducer hole patch.
http://i12.photobucket.com/albums/a2...r/kneekeel.jpg

and a decent overall view of the tabbed in knee
http://i12.photobucket.com/albums/a2...layer/knee.jpg

next up - on to fairing out the transom, also need to add in a new mounting plate for the bilge pump and float switch - the original plate was screwed at all 4 corners directly down into the fiberglass of the hull, only one screw was still remaining - new one will be bonded.

Bill

warthog5 08-12-2005 01:40 PM

Re: a little more progress...
 
Bill, This is ment to be helpful for next time. [img]/images/graemlins/smile.gif[/img]

Before installing those piece's, they should have been run thru the tablesaw and the edges cut at a 45deg angle. This will make your fiberglass conform to the surface that they are attached to with a smooth transition.

You can get the same effect if you will run fillet's around the permiter, but it's more work. It's the only option you have now that they are installed like they are.
On the top exposed edge of the knee itself [where the 3 layer's are] The outside edge's should have a router run around it with a round over bit. This will make the glass conform better around it exposed corner's.
The next thing is to use lighter weight glass. That heavy Roven Woven doesn't like to conform around a tight radius.
I'd suggest multiple layer's of 9oz or 12oz to conform around the outside knee radius and biaxle +45/-45 to cover the rest. It will conform around the inside corner's well, if you put some fillet's in there.

http://www.classicmako.com/bobby/knee.jpg

oldbluesplayer 08-12-2005 04:33 PM

warthog - points well taken...
 
I find myself sometimes getting lost in all the little details..

at least twice I've had the resin in the pot, just about to start adding hardener, and realized I had yet another get-ready task to do first, before I pulled on the gloves and started the clock on a batch.

It's certainly a learning experience, getting up close and personal, so to speak

for the next time - I'm hoping there isn't one. After moving up thru 5 boats over the years, this one is intended to be the return to a trailerable, manageable, can upgrade the power without tearing the boat apart (hah) boat that can last me for awhile, and do the things I want to do (reason I got the cuddy, instead of a cc).

and I suspect, by the time I get done fairing the outer transom, that I'll agree with Ed, that inside out is easier, but I'd still be adding the knee to this boat. But then, given that the boat is 32 years old, and probably only had an expected design life of 20 years or so, it doesn't owe anybody anything.

Bill

stoney 08-15-2005 08:57 AM

Re: warthog - points well taken...
 
Recoring from the inside is definetly NOT easier.
Remove deck cap, remove motor well, cut and grind until you drink soo much you need to join AA. My friend has a 76 23CC that was done professionally from the outside, the gelcoat match was redone prefectly and you can't see that the repair was done except that there is no alumunum trim because it was all faired in perfectly. He runs his boat very hard, and there is not a crack anywhere.
I did mine from the inside because I wanted to get rid of the useless livewell and the extra weight. The boat now sits higher and when drifting the motor well does not fill up with water in a rough sea.
http://i15.photobucket.com/albums/a3...epairs5_14.jpg
I'm glad to hear another engineer thoughts. Keep up the good work. Paint the bilge with white gelcoat when done and everyone who knows boats will be impressed.

warthog5 08-15-2005 01:01 PM

Re: warthog - points well taken...
 
stoney Look's like you used Cossa or Penski board?

http://i15.photobucket.com/albums/a3...epairs5_14.jpg

Shurwin William's Tile Clad HS epoxy paint make's an outstanding bildge paint. It was designed to paint the inside of water tower's, so it will hold up and look good doing it. I used it in my bildge and all thru the inside of the cuddy and console's.


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