Transom wood

[mckinney004]

I've been working on rebuilding the transoms on two Jon boats. Everywhere I go to get untreated exterior plywood I get looked at like I'm crazy. Everyone tells me they don't have it and can't get it. They tell me I can get marine grade or a waterproof sub flooring, but all exterior grade is treated. I can't use pressure treated because of the chemical reaction with aluminum. So where is everyone finding this plywood with exterior grade glue but not pressure treated? I've tried Meeks, Home Depot, Lowes, and Ace.
I've considered using interior grade and hoping the sealants work, but I'd prefer not to. I've also thought about using a piece of cedar or hedge planed to thickness since both are rot resistant. At this point I'm going back to the idea of rebuilding it with aluminum tubing.

 

[wellcraft-classic210]

Home depot will sell CDX plywood that meets your requirement described -- ( untreated / exterior glue ) and its probably the lowest cost option. Its descibed as an indoor plywood as the wood can eventually rot but it is used a lot on boats. It does tend to have some voids ( internal air pockets that can trap moisture ) Keeping it sealed with paint or better yet epoxy will extend its life.

Check out the description on this and you will see exterior glue mentioned
http://www.homedepot.com/p/Sheathin...ual-0-563-in-x-48-in-X-96-in-439606/100024973

Arauco plywood is also sold at some areas in the country at home depot and is a popular choice

http://www.homedepot.com/p/Pine-Ply...ual-0-688-in-x-48-in-x-96-in-799397/202677224


MDO is also an option as its has no voids and is a little less costly that Marine plywood ( used for sign making etc )

Marine plywood would be an upgrade in cost and quality with no voids /untreated wood / exterior glue

If you go with solid wood -- White oak is harder than cedar and somewhat rot resistant // Teak would be optimal as it does not decay when wet and is stronger than cedar also.



Hope this helps

 

[Woodonglass]

This is Sold in ALL the Home Depot's I visit and it is NOT Treated but it is Ext. Grade with 100% waterproof Glue and suitable for your Transom...

http://www.homedepot.com/p/23-32-in-...6057/100061386

If you treat it with this it will last for decades...

 

[lckstckn2smknbrls]

Tell them you want plywood graded ACX, BCX or CDX.
The "X" means it made with waterproof glues. The A, B, and C stand for the grade of the face and back of the sheet.

 

[Ned L]

Yep,... BCX is ideal,.... ACX is a bit 'fancier' and CDX a bit rougher than needed, but any of those will be fine.

 

[gm280]

If you do use even CDX, and there are any exterior voids, mix up some either epoxy or polyester resins and some cabisol filler and fill in the voids. Then sand smooth and you have a very solid material. JMHO!

 

[uncndl1]

I went to Home Depot early one morning two weeks ago, and asked the guy for help. Settled on BCX plywood with a green stripe pained acroxx the edge of an entire stack. There is a stamp on it that says B-C Group, Exterior, Thickness 0.453. He told me that this is BCX and used for exterior and is untreated. I bought this and layed out my pattern for the transom, cut three identical pieces. Glued together it now measures 1 1/2 inches thick. The guy helped me sort through the stack, and found one with very few areas on the "c" side that needed patching. I made sure these faced inwards with the "b" side out in my sandwich. Since I have a small car, he even ripped the 4 x 8 sheet lengh-wise into three pieces to make transportation easy for me home. Hope things go well for your project.