What type of plywood for transom?

[ArizonaNative]

I need opinions on which wood to get for the transom on my 1984 Bullet 19V rebuild. The transom is 1-1/2" thick, so two pieces of 3/4" will be fine. Question is, which type of wood? I'm in Nebraska and nobody carries marine grade plywood. I have done some research where others have used Arauco Plywood, which is available in my area. I have also read where people used exterior grade Fir plywood. Either way, I would soak the plywood with a few coats of diluted epoxy resin.

Will the Arauco Plywood fit the bill?

Thanks

[Skeet'r89]

Marine ply is similar to other plys except that all voids are plugged and filled in marine ply. This makes it stronger. Haven't evr heard of Arauco Ply.

[Hometownhandyman]

If you're real desperate try to use concrete forming plywood.
Or use some solid ash, perhaps.....If I am wrong, correct me please.

[javelin90]

I have heard other wood you speak of. I was researching it before doing mine. If I remember it was pretty expensive. I used marine grade plywood and it is as skeetr mentioned there are no voids in the wood. Whatever you use be sure to coat both sides of the wood w/ epoxy or polyester.
g.

[omcforever]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by javelin90 &raquo;</TD></TR><TR><TD CLASS="quote"> Whatever you use be sure to coat both sides of the wood w/ epoxy or polyester.
g.</TD></TR></TABLE>

[mideerslayer]

epoxy or polyester?

Where would you get this?

[Skeet'r89]

"epoxy or polyester" Fiberglass resin
West Marine or other boating supply stores, online.

[Chub Lake]

Home Depot carries it under a 3M Bondo brand. On line just google epoxy or polyester resin. West Marine or TAP plastics. Buy by the gallon. Should be between $30-$40 per gallon for polyester resin. Epoxy is quite a bit more.

[omcforever]

U.S. Composites,,,,,

[mideerslayer]

Ok sorry for all the questions, but i was looking at Depot and they offer some type of epoxy that is used to seal garage floors. Would this type of epoxy work?

I know i sound cheap, but i have to watch every dollar, during my restore project

[sarmst100]

I think that would be more of a type of paint and not what you are looking for.

[ProcraftMike]

I highly recommend using epoxy resin over polyester. Tests have shown that epoxy resin does a much better job of penetrating and bonding wood. Polyester, in my experience over time, will delaminated and start to seperate from wood. It doesn't seem to penetrate the wood as well as the epoxy does.

Epoxy resin is more expensive, but I would rather pay an extra $25 for it, given that it is superior to polyester, when applied to wood.

[ranger230v]

What Mike said

[omcforever]

Polyester is more prone to absorb moisture/epoxy is not,,,,

[Largemouthlou]

Jamison, not sure if you read this yet or not..

http://forums.iboats.com/showthread.php?t=304639

Have you talked to any of the suppliers about having the marine ply special ordered,, (Lowes, Homedepot)

[javelin90]

I agree with mike. I used epoxy over polyester. I noticed in my javelin that the polyester on the original stringers had allowed water to penetrate the stringers where they run along the floor inside of hull. I could see where the rot was and water inside the polyester fiberglass cloth. I like the epoxy better and it is easier to work and you have some control on cure time depending on the hardener, slow, medium, fast. If your working in cold temps. you want the slow hardener. I stuck w/ the slow as i could use it in cold or hot months. I used wood flour incombination w/ the epoxy to fillet my joints where the transom met radius corners on inside of hull.

I got my supplies from Boatbuildercentral.com
I was new to epoxy and Joel was great giving tips/techniques on using the epoxy. It does cost more but if your going to fix it and want a good fix to last a long time i'd use epoxy.

Also if you use epoxy make sure to pre-fit all the pieces of the wooden transom before setting epoxy. I used marine grade plywood due to less voids in the wood. Depending on the type of boat and make you might need to use 3 separate pieces of wood for the transom to get the original thickness needed. I got my three pieces together and used biaxial fiberglass cloth between each layer when epoxying the three sheets together. The biaxial cloth fibers run at a 45 degreen angle and give it mroe strength. I rotated each piece of cloth between each board to ensure the cloth was running in different directions.

I did not place cloth on the bottom of the board resting on the floor nor the top board. i used a scrap piece of osb plywood to build a jig to ensure once i set the three pieces to glue together that they would not shit. Then i set (5) 8" cmu blocks on top and aloowed it to sit for 24 hours depending on the temperature outside. If your mechanically inclined or have a good grasp of the concept than it is not impossible but just take your time when re-building the transom.

Once i had the transom glues together than i went and added the biaxial cloth to the top and bottom board. You want to make sure you encapsulate the wood with epoxy to ensure no moisture penetration.

Once the transom was glued and i made sure it fit without issues i them used wood flour w/ silica and mixed it togehter w/ epoxy and set the wooden transom in. I used this combination to help keep the epoxy from sagging and allowing voids between the inside transom and the boat hull.

I used a 2x4 on the outside and inside at the top along w/ c-clamps to make sure the transom was held in place. Now i did predrill out the two lower mounting bolt holes. This allowed me to use bolts w 2x4;s at the bottom/inside hull to keep transom secure. You have to be sure the boat hull is secured against the wooden transom cause it not the hull skin will become loose and delaminate from the wood.

Once you have the transom glued in then i would pre-drill out the top two holes. NOW MAKE SURE BEFORE YOU DRILL Any holes into the new wooden transom you dbl. triple check exactly where the outboard motor will attach. I got lucky and the outside skin on the back of transom had not been overdrilled or gouged out. I used a piece of plywood w/ 2x6 and drilled the holes from the outboard motor onto the wood. I then used C-clamps and secured the wooden piece to back of boat and drilled the 4 motor mounting holes. Make sure when drilling the motor holes that your at the correct thickness. Might not hurt to use metal tubes inside your 2x6 template ot ensure the correct angle.

I oversized my motor holes by a 1/2" and the reason for doing so was in case the 5200 silicone failed inside the bolt holes than the wood would be protected. I used a combinations of wood flour, silica and epoxy. It worked great. I then added a 1-1/2" place from bolt hole to bolt hole to spread the forces along the metal bar and prevent the bolts from pulling into the holes. Now if the boat was to ever hit something i'm guessing the whole rear would go as i did this and beefed up my knee braces also.

Omc (javelin) used a 1/2" of plywood for each of the two knee braces. I doubled two pieces of knee braces making them 1" wide. it did add weight but it had a 225 hp on the back.

I know this is a long post to read. Once you begin your project post pictures on this forum and you will get alot of good help from the guys on here.

Keep us up to date, Garland

[ArizonaNative]

Thanks for the insight everybody. I had planned on using epoxy - no question about that. My project has been on hold for way too long and I really need to get back in gear to get it done. I just can't find the doggone marine plywood anywhere around here!! That's the sticking point right now. I'm going to inquire with local lumberyards about the possibility of ordering the marine plywood. I hope they can.

[javelin90]

I found mine at a millwork lumber yard. I think 84 lumber can order it for you also.

[javelin90]

any luck on the marine plywood?

[mcisaac inc]

You need to use British standard 1088 marine plywood or BS1088 for short . 3/4 inch runs around 100.00. Epoxy resins are much more user friendly . I like MAS brand. for fiberglass repair. You can paint or gelcoat over it. Jamestown distributors carries most repair supplies. google marine plywood for a supplier near you............markmcisaacinc.com