Marine grade plywood / Douglas Fir

A

Andrew Holley

Well-known member
ON my last boat, I ordered BS-1088 plywood, it costed me a fortune, with shipping. A local lumber yard carries AB Marine Plywood, made by Roseburg out of Oregon. It's a douglas fir and is what two local boat builders are using. Specificaly Craver Yachets. Now they are not using for hull like I will be, but they are using alot of it.

I know you cann't go wrong with using the best, but the best costs more money and is it worth it?

Anybody ever built anything out of marine grade douglas fir? If so, your thoughts?
 
I will try to be brief: if you use marine fir or even exterior fir, it will work, but how well and long will be the question. Lots of people (me included) ahvae used and use it to save on $ but dont realize it will draw more epoxy and it "will check" not might, but "will eventaully" resulting in more costs to repair. While it will save you in $ up front hte $ will be spent in extra epoxya nd a ply that will check at one point leading to costly repairs. Many builders use extreior or marine fir without to many problems and will give it a thumbs up for boats not in tha water all the time. lots of the oregon dories I have seen are built in exterior ply with chop glassed hulls and have been around for many years... but in the long run you are always better off with one of the BS marine plys.

The yacht builder is likely using it for interior pieces.
 
Everything I have read about Marine fir ply is it will check unless you glass both sides..not just epoxy saturate..but glass cloth. Add that to the cost per sheet. Also, check to see how large of voids are allowed in it. I think Roseburg has a website. I sold , pretty much exclusively, Roseburg plywoods for years and they were the Caddy of the western fir plywood manufacturers. I think they are on hard times now with all the import stuff, osb, big box selling cheap southern yellow pine and just trying to get veneer from the forest past the huggers.
 
Two thoughts:

1) When/if you go to sell, you'll be glad you spent the $, and,

2) when you think about the fact that you used the best, you'll feel better about yourself ; )

If it's like my boat, it comes out of the water after every use and you would probably keep it under reasonable cover. So, the thing is going to last no matter what, unless you use a really cheap grade of lumber and/or glue and leave it parked under pine trees with a ballast full of leaves and water.

I'm a "best of materials" snob, and that's why I don't have any money. Buying a new pup recently didn't help either. Looking forward to the build pics Andrew, good luck.
 
Andrew,

Check with Noah marine. Their shipping charges were pretty good when I ordered my wood. Fir will check if it's not glassed. But you can get 3 oz glass that won't add too much weight.




Chris
 
if I read this right, the main concern is checking right?

so, we all understand, the outside of the hull would be glassed correct Andrew?

there is one side down...

Inside of the hull? don't most of you put some glass on the insides? most plans/pics I have seen on here guys are doing the inside as well...

should that not solve the "checking" issue with this?

Would it be acceptable?

Just looking for thoughts. Thanks for the post Andrew...
 
Eric, most of the insides are just several coats of epoxy and then painted. With good Okuume or meranti that's all theat is needed..with Fir you would want to glass cloth it. Granted, 3oz would probably be enough and if you took REAL GOOD CARE of unglassed Fir..and painted or brushed epoxy into every check as they happened, you would be ok. Personally, I don't take great care of my equipment and would rather spend 10% more to have good equipment that puts up with me.
 
My biggest concern would be glassing the plywood itn eh bildge, that is something that no one does.

I used fir on my cockpit covers (hatch covers to lock the boat). Glassed the top and 2-3 coats of epoxy onthe bottom with paint. Bottoms are checked. They are fine for covers, but in a boat they would suck water.
 
Andrew-
With fir, know that it is not a situation of "will the fir check" it is more of a "when". Glass and epoxy (on one or both sides) will not stop checking - may halt it and pro-long it from happening but it will not stop it. It is common beleif that expoxy and glass on both sides completely stops water and moisture penetration - which is not always the case. Fir will check, it is an quality of the wood, regardless if you have glass on it or not.
 
The goal of my post here is to show how smart I am.

Epoxy is not waterproof. It does not "stop" moisture from entering the wood. So, the guy who said that checking is a matter of "when" is absolutely right.

Seriously, I learned how much wood breathes during the boat building process.
 
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