Material choice? Marine grade plywood

[Ben]

This is a question on marine plywood for the outside skin sealed with cpes, then primed and painted or covered with frp.Ok,so let me ask this what type would you use hydrotek? Or okoume? Or does it matter? It's going to be a stressed skin build following the steps from Steve Frederick shop manual that I purchased today. I have read thought parts of it and found some of the answers that I was looking for. Thank you Steve!! This is going to be the first of many questions that I have as I am new to this forum and this style of hobby.

[Shadow Catcher]

I know a local builder who uses Marine grade and triple coats it with polyurethane, then skins it with aluminum.

[Lgboro]

I used cedar ripped and planned to size for framing and cedar strips on the inside. Just floated aluminum over the outside. There are many methods and wood combinations that have been successfully used to built teardrop trailers. I wanted as numerous conveniences built into my tear and that required me to use light materials to keep the tow weight low enough to tow with a Jetta TDI.

[jonw]

I used 3/4in Okoume marine ply for the floor and 5/8 Meranti marine ply for my walls. They are both just different types of mahogany. Unless you are going for a specific grain pattern or color look I suspect the hardness and strength of each is comparable and either would be fine for any teardrop purpose.

IMHO the advantage of marine plywood is the use of waterproof glues, no voids, and all plys made from the same (hard) wood as is on the face. Hence no delamination from moisture, and any surface gouges will be less noticeable until repaired.

Personally I don't see the need to use CPES or other epoxy if using marine plywood. I just coated the bottom and exterior sides of mine with Helmsman Spar Urethane and it is doing just fine after a year.

It costs more, but should last longer with fewer problems, and can save finishing time if you are going for the woody look.

[Ben]

Well I called that plywood place and the only 4x10 sheets they have is in 1/2" and their aqua tek so that's what I'm getting. Now the is do I just get 2 sheets or do I get more?

[absolutsnwbrdr]

An alternative to marine grade ply would be MDO plywood - its used to make exterior signs. I used it on my second build. Not sure how much marine grade plywood is, but my 3/4" 4x10 MDO was about $115/sheet. Well worth every penny. Lumber yards should be able to get it. If not, contact a local sign company... thats where I got my two sheets.

[Ben]

The 1/2" aqua tec was 139 a sheet and a day trip to Lake Erie. I finally found some Baltic birch ply 3mm thick 5x5 sheets in Columbus for 15.50 a sheet. I'm going to have it delivered to the house. Because of not being able to get there for their will call hrs.

[doug hodder]

It's just my opinion, but I'd only use the marine grade mahoganies on a woody. I've built 2 using the Okume and on those, I only got the thinnest material that I could get and then laminated it on some regular old exterior grade ply. I only did it for the mahogany look.

My original '49 Kit was just regular old ply and it was in great shape after 30+ years, (aluminum skin). If it's going to be hidden/covered with another material or paint....it seems like a waste to put the dough into the high dollar ply that won't be seen. Regular ply, with well sealed edges will give you what you want for less money. My 3rd build was just exterior grade ply with epoxy and auto paint over it and it's got 5 years on it now...no problems with the body on it. Other opinions will probably vary. Doug

[Ben]

I honk there has been a misunderstanding of the moby 1 I am referring to. http://dornob.com/rugged-teardrop-trailer-home-for-radical-off-road-adventures/ not a woody. I'm not quite ready to build a woody just yet that's just a little over my skill level for right now.

[mikeschn]

I used Baltic Birch plywood on my first Winter Warrior. It was covered with Exterior Oil paint.

Within 2 years it was delaminating.

I would recommend only using Marine Grade plywood or equivalent if you are not skinning with aluminum.

I am currently doing a build with underlayment from Menards, that has the same glue specs as Marine Grade plywood. It'll be covered with Polyester Resin.

http://menards.com/main/building-materi ... c-5698.htm

Mike...

[Ben]

I scored some free material so I decided to make some saw dust and started to get some boards down to size for my off road benroy here's my profile cut out