another transom job in the works -

oldbluesplayer · #1 07-18-2005, 06:12 PM

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 · #2 07-18-2005, 07:01 PM

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--------->

NoBones · #3 07-19-2005, 12:55 AM

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 · #4 07-19-2005, 12:57 AM

Oops, No picture. [image]http://

[/image]

FELLOW-SHIP · #5 07-19-2005, 11:02 AM

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 · #6 07-19-2005, 12:06 PM

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 · #7 07-19-2005, 05:26 PM

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 · #8 07-19-2005, 05:59 PM

i think it is #403 that make the peanut buttah

captj2 · #9 07-19-2005, 06:38 PM

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 · #10 07-20-2005, 12:52 PM

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