1970 gulfstream makeover... Somewhat

[nurseman]

Glad to hear your foot is on the mend! Tent looks like a nice shady spot to do awesome things with glass! I would say that if the regular ply you have access to is not dry and straight, I would go for the good stuff. Here, the ACX or BCX is more than good enough, but it is usually dry and mostly straight. If a person is somewhat choosy, they can get quality sheets. Bottom line is to use the materials that will do the job to the level you deem acceptable, and you're right, at this point, what's a couple-a-hundred more, right?

 

[kcassells]

Tent is a 10x20 from Costco. We had a high pressure system that brought some rain and wind, to the tune of 50 mph, and over a hundred on slopes of Mauna Kea on the Big island of Hawaii. My wife called me up freaking out because everything was blowing around, so I left work to tend to matters. A gust must of caught it right, because it bent two of the end poles over. If you look in the pic at the back corner you'll notice the pipe isn't straight. I've used marine ply in the past and it was a lot lighter than regular ply. The exterior ply that we get here on the island is usually wet, twisted, etc. The marine ply has no voids, dry, straight and light. Do the voids make that much of a difference? I figured I'm in this deep whats a couple hundred more for better material.

Like Nm said...But voids get filled and sealed. Totally your call. I suspect that marine is more available on an island than at our local stores. Probably here the majority uses ply as above vs. marine. I think thats a fair statement to make in regards to the people on this website. Others use straight up lumber like lobster boats, shrimpers and fisher boats. K, I just wannna fish not make the taj mahal.

 

[kinaiahi61]

No Title

Does the marine ply in your areas meet the BS 1088? The one here does, or they did the last time I bought some. However, there's another regular lumber yard here on my way home that I'll check tomorrow on the BCX ply. I bought all of my framing and wood material from when I built my house. They keep their wood under cover and seem to have better quality. What should I look for besides wetness, straightness, voids, amount of plies? How wet is too wet?

 

[nurseman]

I am unfamiliar with the BS 1088 rating of Marine ply around here, as I didn't use it. But as I understand it, in order to be listed as Marine Plywood, it must meet that standard. I could be wrong.

Here are some links about moisture content in plywood.

http://blog.positiveindians.in/plywood/plywood-moisture-content.html

This one has a nice table for acceptable moisture % based on location

http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr190/chapter_13.pdf

Hope that helps!

 

[kinaiahi61]

I am unfamiliar with the BS 1088 rating of Marine ply around here, as I didn't use it. But as I understand it, in order to be listed as Marine Plywood, it must meet that standard. I could be wrong.

Here are some links about moisture content in plywood.

http://blog.positiveindians.in/plywood/plywood-moisture-content.html

This one has a nice table for acceptable moisture % based on location

http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr190/chapter_13.pdf

Hope that helps!

Thanks for the info. Gonna see if I can find some good sheets tomorrow. Would be nice to save a few hundred dollars!!! Bet the wife would be happier too.

 

[Woodonglass]

Ask them if they carry Floor Underlayment Plywood. Typically here in the states this specialty plywood is manufactured with more plys, less voids and must be made with 100% waterproof glue which makes it ideal for Marine use. Typically used for upstairs Bathrooms, kitchens, utilities...anywhere that water could be an issue.

 

[kinaiahi61]

went to the lumber yard this morning on the way home from work. Found some BCX in 5 ply but after the top one, all were wet. The worker said I could dry them out by standing them straight up. Space them out and wait for them to dry. They also had quite a few voids in them. Stopped at home cheapo and their stuff was a lot worse. All of our exterior ply here are borate treated. Will this affect anything. Is it acceptable to just buy the wet ply and dry it out.

 

[Woodonglass]

Uhmm that's what we call Pressure Treated here in the states. Borate keeps the Termites away. Are you sure they don't have any Plain ole ACX Exterior Grade Plywood. Is it all Pressure Treated?? Did you ask what they use for Interior Flooring Plywood?? Does anyone carry MDO plywood? NOT MDF!!! It's called MDO (Medium Density Overlay). A quality lumberyard might carry it. NOT Lowes or HD.

 

[kcassells]

yawza yawza yawza...I didn't expect plywood grades like ac, bc etc would be such a problem. I thought I recalled reading that "treated exterior grade" had issues with bonding to poly, epoxy glassing. Can anyone chime in on that for me. Hmmm
All HDeblows lumber here in Pa. are in enclosed stores. Most of the plys I've seen are usually 5 and with voids, nots but dry. acx and bcx maybe 7 ply. Not sure.

 

[Woodonglass]

Yep, NO RESIN likes to stick to anything that's WET!!!! Treated Plywood takes a Long Time to Dry out and even then the Chemicals can Leach out and cause De-Lamination issues. I Hate that stuff when it comes to boat building

 

[kinaiahi61]

Uhmm that's what we call Pressure Treated here in the states. Borate keeps the Termites away. Are you sure they don't have any Plain ole ACX Exterior Grade Plywood. Is it all Pressure Treated?? Did you ask what they use for Interior Flooring Plywood?? Does anyone carry MDO plywood? NOT MDF!!! It's called MDO (Medium Density Overlay). A quality lumberyard might carry it. NOT Lowes or HD.

There is a place that carries MDO (Specialty Lumber) but it isn't much cheaper than certified marine ply. The guy that I talked to said that its painted on both sides. Does the resin stick to this, and is this usually how MDO is? I used to work construction and I don't recall any exterior ply here that isn't borate treated. I can ask the guys at Specialty Lumber (marine ply sellers), I looked at everything HD had today and didn't see any exterior ply that wasn't borate treated. Yes we have termites and thats what the borate is for. Most everyone here uses treated ply for the floors since theres termites. Everything we build with is pretty much treated wood. Only things that aren't are the finish work wood like cabinets, doors, or some trim. Never built a house with anything else. Thanks for the help guys

 

[nurseman]

Marine Ply it is then!!!

https://www.youtube.com/watch?v=-3dXBoN1lFE

 

[Woodonglass]

Can't use painted so I guess Nurseman is right...Marine Plywood!!!

 

[kinaiahi61]

Shoot, just got off the phone with Specialty Lumber. He said that the MDO isn't void free, and he doesn't have anything that is exterior without the borate treatment. He also didn't recommend glassing over the paint on the MDO. He said I should just wait. He does have 3 3/4" marine ply for $120 ea. He also said that the shipment of 1/2" isn't going to be here until the 20th. I was planning on using doubled up 1/2" ply to replace the 1" solid wood stringers that were taken out. If I use the 3/4" it would be larger and probably stronger. They just cost $40 more a sheet. Maybe I should order all of my fiberglass supplies, then I can thicken the hull. Only drawback is that it'll be a mechanical bond only. Or I could order and get started on the fish box that Im gonna build out of ISO foam. That way I can get back in the groove of laying some glass. Just would hate to sit dormant for a couple more weeks. Need this done already!

 

[kinaiahi61]

I just called another company here and I was thoroughly surprised that they sell marine plywood. I need to go and check it out, but they are $85 for 3/4" as opposed to $120 from Specialty Lumber. Not sure if its the same quality, but for that price I could go with all 3/4" ply for the same cost as the 1/2". Thank God! Hopefully its good stuff.

 

[kinaiahi61]

Went and checked out the marine ply for $85. It looked like douglas fir marine ply. It was pretty heavy, but it was dry, straight, and from what I could see, void free. I don't wanna use all of that for the whole boat because it would be too heavy. I know that the other more expensive marine ply is a lot lighter. I'll go and check that out. If not I can use the less expensive in the transom and do the rest of the boat with the 1/2" good stuff.

 

[kinaiahi61]

Thank God, finally got all major grinding done and then some. Been reading on the douglas fir marine ply and said that it is more resistant to rot than Meranti, anyone know if this is true? Also found some that say that fir is stronger??? I'll try and get some pics tomorrow if possible, the camera wasn't cooperating today. Mahalo

 

[Woodonglass]

Doug Fir is heavy but VERY rot resistant.

 

[kinaiahi61]

Should I use this as opposed to the meranti for the transom and the stringers. The stringers were 1" solid hardwood. Double up the 3/4" for a 1.5" stringer. Any input? Then use the 1/2" meranti for the bulkheads and floor? Too bad the douglas marine is only 3/4".

 

[Woodonglass]

What's your guess-ti-mate on the weight of the 4x8 sheet of Doug Fir plywood?