Advanced board wood waterproofing ...

[GPW]

Since it looks like wood is still a practical ( and easily accessible) framing material and does find some good use in a Foamie trailer construction. We must find a way to make it completely waterproof ... I had an idea ...
Saw some large PVC pipe , must have been 8” dia or even bigger... Cap one end off , prop it up on something so its on a 45 degree angle , Then fill it half way with “The Mix” , and insert a couple boards till they are covered completely with "the mix" ... How long it would actually take , to become Mix-logged’ I don’t know , but ideally it should fill every little end grain and pore in the wood ... making the board “plastic” and impervious to water absorption ... Sounds a bit far fetched, you could probably just get a big tray or Tub and soak it in that .... Whatever !!! The idea is to fill the tubes in the wood , “plasticizing”, eliminating many problems in the future , and it should even cut better , like cardboard treated with "the Mix" does ... Note : You may find it easier to cut all your pieces to length first and soak them as “shorter" pieces instead of full length boards , that way , logically , the Mix could penetrate better and not have to go so far to Completely fill the tubes...

The idea , soak the wood in the Mix ( or Thompsons/whatever you like ) as long as it takes to really do some good ... Just another idea for improving the quality and Durability of our trailer builds ( even non Foamies ) . I’m sure everybody will come up with their own ideas of how they want to do it ...

[TeriL]

Simply soaking the wood in a solution for a few hours or days will only saturate the surface and end fibers. Trapped air will prevent any solution from deep penetration. Wicking is the mechanism for any penetration. Soaking it long enough will eventually fully saturate the wood but how long are you willing to wait? Then you are face with the interior having to dry or cure which would take even longer. Varnishes and polyurethane varieties polymerize by a chemical reaction with oxygen. https://en.wikipedia.org/wiki/Varnish Even if the wood were completely saturated with a varnish mixture, the surface would cure first and start sealing the interior from ready oxygen diffusion and subsequent polymerization. Full polymerization could take years and out gas any solvent in the meantime.

Vacuum infusion would be somewhat more effective and corresponds to the pressure treatment used for commercial pressure treated wood. As you probably have observed at the box stores, pressure treated wood is very wet as the water solvent for the preservative used slowly drys out. It can take weeks or more for thick pieces.

Bottom line is what you and others have been doing, keep brushing/rolling on the thinned varnish until no more soaks (wicking) in. For all practical purposes, it's good enough. Soaking the ends of lumber (end grain) in a bucket of mixture for a few minutes would be a good idea too as rot usually starts on the ends.

I know your eyes glaze over with technical discussion but "If it's not physics, it's opinion". Engineering is applied physics.

-- Engineer

[Talia62]

Add a screw plug to your PVC tube, and drill it for a vacuum fitting, so you can put the whole thing under a vacuum.

[tony.latham]

One problem with varnish-like finishes such as oil based polyurethane––and I do like the stuff–– is that when it dries it remains somewhat porous. The curing process involves oxidation (I think) but a lot of it is simple evaporation which is where the porosity develops. Multiple coats help.

Modern wooden boatbuilders use epoxy. It doesn't cure by evaporation. It sets up. Coat a chunk of plywood and throw it in a bucket of water. When the water has disappeared into the air, the plywood will be fine.

I swear by the stuff.

Tony

[GPW]

OK, very interesting ... Thanks !!!

[mikeschn]

Also, it's probably only important to treat exposed wood with the mix. Something that is covered with canvas and TB that is never going to get wet shouldn't need such extreme measures.

But ask me again in 10 years... I treated all my wood in the mad dash with the mix, and I am waiting to see if anything happens...

You got 10 years?





Mike...

[GPW]

Mike , I will also keep treating my wood with the Mix ... Knowing full well , it has worked for me into the past ... And does protect in our Humid and rainy conditions ...

Now about that penetration , what about a porous wood like Red Oak ? .... It’s so open you can blow air through it ... ( try it , put one end in a bucket of water and blow on the other end ..... Bubbles ... ) I guess (schmaybe’?) we could apply a vacuum to one end and suck the mix through the tubes ... I have still not given up on this idea .... as yet ...

Of course , we could use the New PVC “boards” ... but they are pricy ... and yet untested by this community ...

Note: for the newcomers who don’t know where "the Mix" comes from .... Here is where I got it .... some time ago ... http://www.feltondesignanddata.com (WARNING: some reading may be involved)

[Talia62]

I've had pvc board trim and fascia on the outside of my house for about ten years now, and it's indestructible. Super easy to work with, but a bit pricey and kind of heavy for a light trailer if you're looking to keep the weight down. That sh*t don't rot, though.

[GPW]

T’ with as little as we’d actually need , it might be a good “investment” ... Now we just need a Lottery winner to try it out for us ....

[KCStudly]

The thing (from past discussions) about the plastic "wood" boards that doesn't pass muster is that they sag and/or require more frequent structural support; so not only are they heavy but there is added structure needed to hold them up adequately.

Maybe there is a place for them, but it is not something that I want to experiment with. Don't let me stop anyone else from doing so, tho. I'd be happy to see something come together. Then we can compare notes as to whether it is still lighter and more thrifty than skinning a more traditional material with epoxy and glass. Just saying, there are a lot of ways to do a thing that don't make it easier/better/cheaper in the long run.

[GPW]

KC , I still think there is some promise with PVC square tubing which is very stiff....

[GuitarPhotog]

KC , I still think there is some promise with PVC square tubing which is very stiff....

The price of that stuff is pretty stiff also. 1" sq X 10 ft = $2.57/ft, 3" square $9.65/ft. And not UV stabilized, so you couldn't use it anywhere in direct sunlight.

I think that overall if you are looking for strong, light, and cheap you aren't going to beat foam with canvas and glue over. Minimal wood framing at required hard points only (i.e., door and window frames, galley hatch attachment, and attachment to trailer chassis).

Coroplast (corrugated plastic sheeting) is light and easy to cut and bend but requires special adhesives and paints and is not long-term stable in sunlight. My 4' X 10' trailer is almost 70 years old, has never leaked, and is as strong today as when it was built in 1948. It's made of 0.050 aluminum sheet riveted to 1" angle iron on a 1" plywood bottom. It weighs less than 800 lbs empty. Strong and light and durable do not necessarily come cheap.

My $0.02 worth
<Chas>

[mikeschn]

Glen,

I'm testing those new pvc boards. If you recall, I'm using them for my fender wells.

Mike...

Of course , we could use the New PVC “boards” ... but they are pricy ... and yet untested by this community ...

[VijayGupta]

anyone used this stuff? http://lpcorp.com/products/siding/lp-sm ... im-siding/

[dogscats]

After looking at post with the wood ring would there any thing wrong with a fiberglass ring .