What exactly is marine grade plywood?

[tr918]

Is marine grade plywood nothing more than exterior grade B-C or better with no knots?

 

[Nos4r2]

Re: What exactly is marine grade plywood?

No. Marine grade ply is exclusively made of hardwood. May have more plys too depending on what/where you get it-I have some 5 ply marine ply in 1/2" here from an old transom reinforcing plate.<br /><br />There MAY be differences in the glues used too.<br /><br />Exterior grade (at least over here) has hardwood outer and a softwood inner ply in 3-ply at least-never looked at anything else.

 

[tr918]

Re: What exactly is marine grade plywood?

Thanks. That helps clear things up. I was asking b/c some of the lumber yards here either have marine grade or do not know what it is. The ones who do not know suggest using the exterior grade. It also helps explain the high cost of the marine grade wood.

 

[crab bait]

Re: What exactly is marine grade plywood?

but NOS is from the UK.. <br /><br />most/all marine ply here is from douglas fir ...the same as most b-c ext.. some b-c ply is from yellow pine..<br /><br />marine is SUPPOSE to have no hallows/voids.. most the time it's true.. the reason for so many 'footballs'..<br /><br />b-c an marine ,,have the same w/p glue..<br /><br />marine does have more plys an is stiffer cause of that.. but also the plys are flip-floped/staggard on 45 degree.. opposed to not..<br /><br />about it.. <br /><br />have found some good a-b exter. that was marine void wise for lots less.. but less plys an flimsier..

 

[nort]

Re: What exactly is marine grade plywood?

BS1088 marine ply is wonderful stuff. It is made from tropical hardwood so it does not check. Both sides have an a finish and there are no footballs, no fillers and no voids. It is expensive and may not be available locally. However for building wooden boats or wood core boats it is well worth the money. I ordered 10 sheets from BoatBuildersCentral and the average cost with shipping was $43 a sheet. My latest boat building experience has been much better than the cheap plywood I used the first time. This boat will have a much better finish and will be much stronger.

 

[tr918]

Re: What exactly is marine grade plywood?

Thanks, Nort. I was quoted $73 dollars a sheet locally for marine ply. $43 with shipping sounds better to me.

 

[bigbad4cyl]

Re: What exactly is marine grade plywood?

i saw 1/4 inch for 43$ maybee