Transom repair
 

I’m looking for comments and opinions from those who have done a transom replacement (and height increase to 25”) on a standard Potter era 20’CC.
Questions are-is the red cut line O.K as shown?
How are the flat panels (labeled A) attached to the inside face of the transom?
Is plywood the material of choice, or are the composites (such as Coosa) that good?
Any Coosa suppliers in the greater Boston area?
[image]http://img.photobucket.com/albums/v2...ed-1Medium.jpg[/image]

Re: Transom repair
 

I would do it from the outside but if you are set on doing it from the inside the motor mounting area and the "A" areas have a putty between them and the transom.
See the pics of my 20' project boat at
http://www.hermco.net/gallery2.htm
:D

Re: Transom repair
 

I have not done the entier transom on my 20 yet, but I will some time eventually. I would say cut directly up from the scupper drains in the floor if you are going to put the piece back in. I may be easier to fair that way. I'm sure others will chime in. I want to raise the boxes to gunnel height like others on the site have. You may want to consider that also.

I repaired my transom in the mid 90's some time way before CSC and I did not cut out the back, or the inside. I went down the middle with a CHAINSAW :o that was when I was young and stuipid. :D I poured about 1/2 gallon of epoxy in there too. That is going to be a bitch to get out next time around. Plan looks good so far. You have the greatest seacraft restorers at you bekon call here. Keep the pics flowing.

Re: Transom repair
 

Is the entire transom shot?

If not follow Hermco's instructions, removing "A" and "A" will be a task unless the entire transom has turned to mulch

Have you looked at this: Hammers 20.

Re: Transom repair
 

Hermco,

No, I’m not set on which side of the boat to approach this problem from. I just thought that was a topic for another discussion. Since we are here now, I do have a few questions about doing a transom from the outside.

Pictures on most threads I’ve seen that have done the job from the outside have made a cut similar to what I show in red.

How do you get bad wood out of the areas I’ve marked as B, and if parts of a new transom are installed in those area, how do you get a bound a bond between the new pieces and the inside of the glass skin?

How do you get the new transom in place unless you divide each new layer (assume two, at ¾” each?) into multiple pieces, and don’t these additional joints tend to weaken the new work?
[image]http://img.photobucket.com/albums/v2...ed-2Medium.jpg[/image]

Re: Transom repair
 

Here are pics of a transom I did for my brothers boss. Quick and cheap. I dig the wood left in the edges out with a hammer,pry bar,and chisel starting at one side and working around. Backfill the edge with putty and glue in the new core,glass and roll on Duratec base primer. Sand flat with 8" Hutchins sander and spray with gelcoat mixed with patch booster from Fiberglass Coatings. Wet sand with 400/600 and buff. Done in 3 days. :D
http://www.hermco.net/Makotransom/DSCN0330.jpg http://www.hermco.net/Makotransom/DSCN0333.jpg http://www.hermco.net/Makotransom/DSCN0335.jpg http://www.hermco.net/Makotransom/DSCN0337.jpg http://www.hermco.net/Makotransom/DSCN0339.jpg http://www.hermco.net/Makotransom/DSCN0342.jpg

Re: Transom repair
 

The answer to that is NO. You have marked every radius to be cut. You want to cut as much as you can on flat spot's. Flat spot's are 10 times easier to repair than the inside corner's that you have marked.

Re: Transom repair
 

I started my transom a week ago and am doing it just as Hemco has described. Had all the wood out in 2 hours. I bought a cheap electric chain saw to get behind the few inches of outer skin that is left behind. So far it is turning out to be a very smooth job. :cool:

John

Re: Transom repair
 

Do it from the outside! Repairing all of those inside areas will take forever-no advantage to that method unless you are rebuilding all the areas to change the layout.

Mark out your cuts and grind BEFORE you cut, as this will save a ton of time when you put it back together and you will have nice and flat areas to glass back onto. Don't worry about putting the wood back in in pieces, the strength of the laminate is in the skins, the core is just holding them apart. Most foam laminates are plenty strong and the foam is often kerfed every 1"! If you are concerned, just stagger your joints, but it is not an issue.

Follow Hammer's lead, very quick way to do it. Just leave yourself enough room at the edges so you have 3-4" left to glass onto without going around the corner (much more work, as noted by others).

Peter

Re: Transom repair
 

Hermco,

Great pictures. Thanks. How many pieces made up each layer on the project you did for your brother's boss, and how big was the overlap of those joints, first layer to second layer (I assume there were only 2 layers, correct?)?

Re: Transom repair
 

Warthog5,

I agree. I was drawing those lines thinking about a reconfiguration similar to either of these examples.
[image]http://img.photobucket.com/albums/v2.../1174008_2.jpg[/image]
[image]http://img.photobucket.com/albums/v2...t/e349e92b.jpg[/image]

Re: Transom repair
 

alarie,

Any advantage to grinding back (bevel) along both sides of the cut lines before you make the cuts?

Re: Transom repair
 

I use the outside skin I cut off as a pattern for the new core wood. I add new glass to existing inner skin (2) 1708 biax and let cure. Backfill putty the edges and let cure. Then glued (1) - 3/4" and (1) - 1/2" ply together with (1) - 1 1/2 oz mat. Use drywall screws to hold together then remove when cured. Wet out (1) - 1 1/2 oz mat on inner skin and clamp new core in. Let cure then remove clamps and putty/grind. Glassed outside with (4) - 1708 biax and a 1 1/2 oz mat to finish. Roll Duratec base primer and sand flat,gelcoat,wet sand,etc.
I don't see any benefit to grinding before you begin because you will have to grind again after gluing the core in anyway to remove drips and excess putty etc. I don't care for the grinding part but it's gotta get done! :D

Re: Transom repair
 

The spot putty in this pix. What is it?

http://www.hermco.net/Makotransom/DSCN0337.jpg


dcobbett I don't like boat's without a splashwell. I wouldn't have one without it here on the Gulf Coast.

Re: Transom repair
 

Oh, now i remember that project.

Here is probably the only other approach besides the inside or outside;

http://www.classicseacraft.com/forum...er=8395&Forum=,,,,All_Forums,,,,&Words=&Searchpage=4&Limit=25&Ma in=8395&Search=true&where=bodysub&Name=251&dateran ge=1&newerval=&newertype=w&olderval=2&oldertype=y& bodyprev=#Post8395

And area's "A" on my boat was filled with puddy, that was old and cracked. Was not doing much except pieces were waiting to dive into the bilge.

I do not recomment the chain saw (i originally thought of pouring that Sea-Cast stuff) so it was unnessary once i decided to cut the inside liner. There was plently of room to remove the core with any primitave instruments of destruction(chisels etc)

Also this approach gives you the ability to bond new stringer knees into the core and glass all in as one.

Now decide on an approach and get to it, spring is on the way .....

- Nick :D

Re: Transom repair
 

I like to grind first, I think you get a smoother surface when you go to glass it back up. As to the putty and grinding again, I always try and go for it in one step. In this case put in your plywood, putty all edges, squish on the transom face and clamp/screw into place, smooth out the putty on the bond line, wet out and glass your already perfectly flat bevel, peel ply and roll out the air bubbles.

This method is a lot less work, you just have to have your S@#! together before you get wet. It's all in the prep work and fitting. You are not gaining any time by rushing into glue and putty until you are ready to put it all down in one step.

As someone that does this almost every day, I can tell you that efficiency lies in eliminating steps. It may not seem like a big deal to glue on the face, then grind smooth, then glass, but I am already onto fairing the repair and you are still putting down glass.

I also think that you gain a lot of strength by having everything wet at the same time, instead of relying on secondary bonding between wet and dry elements.

As far as the grinding, the easiest way to do a good job is when the pieces are together, held in place by each other.

Re: Transom repair
 

Thanks to everyone for all the input and good advice. I need to drill some more holes to find out the extent of my problems, decide how to approach the solution, then get started!

Re: Transom repair
 

3M premiun filler a vinyl ester putty. Great stuff I have been using it for about 6 years now.

Re: Transom repair
 

I defer to the efficiency expert ........ ;)

Re: Transom repair
 

I am new to this chat room so perhaps this has been already addressed. Can anyone advise what, if any, telltale sign indicates that a transom requires overhaul in the not too distant future

Re: Transom repair
 

bobhoff,
First off, welcome to CSC. Regardless of what type of boat you may have, you'll find some excellent advice here, especially transom repair/replacement.

The most obvious sign is excessive transom flex. Stand on the trim plate of your motor and jump up and down. Another sign is moisture in the core, which is picked up by both a moisture meter and by tapping on the fiberglass with a plastic or rubber hammer. With the hammer, you will hear a hollow sound due to delamination. Yet another sign is dirty water weeping out of motor mounting holes and other thruhulls in the transom. The best way to detect moisture is by driling a couple core samples.

Re: Transom repair
 

Oh Yeah, besides AGE the ole weeping water syndrome. Welcome to CSC bobhoff :)

http://img.photobucket.com/albums/v1.../stripped3.jpg

Re: Transom repair
 

For you guys that raised the rear boxes on the 20's. aside from Marks, did you cut the tops off, raise them and fill in the middle or construct new boxes all together. I plan on doing this in a few years when I rip into mine so I guess I should start planning now. :D