treated ply and rosin

[thejeepster02]

I have heard about the treated Ply eating up alum.<br /><br />But a new one on me....I was told fiberglass rosin wont stick to treated wood. <br />CAN ANY ONE CONFIRM THIS ONE??

 

[Paul Moir]

Re: treated ply and rosin

It's untrue:<br /> Article<br /><br />What is a problem is that pressure treated panels are usually sold as a warped pile of junk, still dripping wet with CCA from the autoclave from which they were freshly removed. This is the root of the adhesion problems - no type of fiberglass will stick to wet wood. <br />If you want to use a pressure treated panel, give it ample time to dry. A month or two indoors would be good.<br /><br />PS - it's the first C (Copper) that causes the aluminum problems. There's enough in it to cause galvanic corrosion of the aluminum.

 

[BillP]

Re: treated ply and rosin

I'll add a little to what Paul said. Early pressure treating processes used petroleum based chemicals. Glasswork over petroleum doesn't give good adhesion...that's the source of your comment on glass not sticking. Petroleum based pt mostly went away about 25 yrs ago, so you can see how dated the material is that says resin won't stick.<br /><br />Like Paul posted, CCA processes don't keep resin from sticking. The APA publishes actual test data which confirms this. Interesting reading. It's all about getting the CCA treated wood dry enough.<br /><br />Additionally, on my aluminum pontoon boat the pt deck is 95% insulated with bedding where it touches aluminum. However, there are places that are bare and it shows no evidence of corrosion. I boat in salt water and the boat has spent most of it's time since 1996 hanging over the water in a lift. There's way more corrosion where ss fasteners touch the aluminum. I'm not sure pt wood corrosion is a serious concern but I've been watching it.

 

[Paul Moir]

Re: treated ply and rosin

BillP - I had no idea about the petroleum based methods. I guess you learn something new every day.<br /><br />I've never personally experienced the aluminum pitting problem either, although I've seen treated wood in contact with it in salt water environments - the only kind we have here. I had assumed this was just a Marine Legend, but a couple Iboats members have posted here where they have had just that problem. It didn't seem very serious for them though.<br /> Recent reporting..

 

[Maximerc]

Re: treated ply and rosin

Fiberglass resin is not a good glue to ANY wood.

 

[jfholijr]

Re: treated ply and rosin

Actually If you pretreat the dry plywood with styrene, it actually helps the polyester resin form a very durable adheason to ply.

 

[MichaelMullis]

Re: treated ply and rosin

I wonder if glueing a strip of rubber as wide as the crossmembers to the crossmembers themselves would work to keep pt from contacting alum. I think that this would also add some insulation from vibration also. Whats oppinion on doing this?

 

[BillP]

Re: treated ply and rosin

Originally posted by baitkiller:<br /> I wonder if glueing a strip of rubber as wide as the crossmembers to the crossmembers themselves would work to keep pt from contacting alum. I think that this would also add some insulation from vibration also. Whats oppinion on doing this?

I think that's a good idea and necessary to keep water out too.