New transom wood - how to hold in place

abl1111 · #1 06-17-2003, 12:21 AM

What is the best way to hold a wetted out new transom in place for a solid cure ? This is from the inside.

Also, any problem w/ using AC ply ( FIR ) as opposed to Marine ply ? FYI: I'm not interested in any transom material other than these two..

Thx

FELLOW-SHIP · #2 06-17-2003, 09:38 AM

I had and barrowed a bunch of sea clamps, plus I used the glue and screw method. I used the sea clamps on the top of the transom and used screws through a lot of the existing through hull fittings on the transom you can use a block of wood on the outside of the transom and a long wood screw or you can use bolts and washers drilling through the plywood and through the existing wholes in the transom. There will be a few arrears you might decide to use that do not have existing wholes that’s OK you can fill them up later. On the 2 layer of plywood you can screw from the inside to the existing plywood of the first layer of transom material. I used ¾” marine grade plywood after the job I decided that if I had to do this all over again I would use 3 layers of ½” instead easier to work with and 6 layers of epoxy on the plywood instead of 4. Now 1 & ½ years later I would use the new composed material ya they cost more but no concern of water rotting 10 years from now either.
Fellow-Ship [img]images/icons/cool.gif[/img]

Finster · #3 06-17-2003, 09:43 AM

What I did was to take two 2x4's run them accross the outside of the transom, drill hole's through both and bolt it tight. And lots of C clamps along the top.

abl1111 · #4 06-17-2003, 05:17 PM

Uh huh. Chris, what did you use as transom material. I have a fiberglass guy helping me who says, ( and I quote ) " if it's done right w/ (2) 3/4" pcs of ply - it will last forever "

I kind of agree w/ him. We are palnning on using polyester for the entire project - even the ply edges.

What d'you guys think ?

Finster · #5 06-17-2003, 05:44 PM

Alan, I used 2 3/4 marine grade plywood and epoxy. Most pro's seem to use polyester and I am not sure why? Maybe price. I've worked with both and like the epoxy better.....what ever.

I've sent you pic's several times, you ever get'em?

Ed · #6 06-17-2003, 09:15 PM

abl111-

Your fiberglass buddy is right. Most of the pros do use polyester resin (unless the boat is made out of vineylester resin- you basically need to match the hatch, so to speak) and two layers of 3/4 inch marine ply. I would steer away from the AC plywood.

As far as epoxy is concerned, I am not so sure it its lack of use amongs the pros has to do with price.....I think it might have to do with the cure time, mixing ratio sensitivity and the fact that most boats are made out of polyester resin.

Don't get me wrong, I think epoxy is a great product especially for guys like us. I just used some penetrating epoxy to seal up some exposed wood around some thru-hulls in my transom.

Good luck

jw · #7 06-18-2003, 12:47 AM

I redid my transom and used two 3/4 inch composite boards, too much involved to put plywood back. I also used the glue and screw method, except i just screwed in screws avery 2 inches. Have the outside faired resonably, just shot some awlgrip and see that i have some more sanding to do.
I have some pics if you want them.
JW

SECF3114M73J · #8 06-18-2003, 01:32 AM

The way I understand it,polyester is used to match the composition of the cloth/mat.The cloth wets out more completely with the poly resin.

PipeDreamsMarine · #9 06-18-2003, 10:10 AM

I did mine from the outside in but I used 1/2 ply that I resin coated then screwed in place with a layer of 1.5oz mat in between each piece of ply, puddying in the corners and voids. I did this 3 times with a final layer of 10/24 on the outside. This hole thing gave me 2 1/4 thick, just the right size for the shoes on the newer outboards. I used polyester resin and polyester putty . Working times are better with the resin and I allways have it on hand in the shop. Plus it seems to work better when you gelcoat the finished project

abl1111 · #10 06-18-2003, 11:43 AM

Thx guys. Pls send all pix, so I have a baseline to look at.

E-mail is [email protected]

Is there a big difference between the marine grade and A/C ply ? I can get the A/C for free.

Doesn't fiberglass have a tougher time adhering to marine ply ?

FYI: ( I don't know if this is useful, but ): Upon removal of the transom, the stringers connecting to the transom ( the foam filled ones ), and a 2.5' section of the 2x4 wood center 'keel' - I have noted the following:

The foam in the stringers seem to be closed cell. If there are voids in the foam, then sure water will seep. But, for the most part the water did not go any further. The wet areas of the stringers were near where the collected water near the scupper's weep into the bilge via a rubber hose. Poor design, but no big detriment to structure.

I also removed a section of the 2x4 center stringer ( to make room for an i/o ). This was in very good shape, although wet. Solid as a rock. I'm sure it would have rotted soon due to the wet. The water got in here via the small hole in the 2x4 that allows water to drain from side to side in the bilge.

Maybe some areas for you to check on your boats...