Wood Sealer - Water Based vs Oil/Poly

[GPW]

You know , one thing to consider too is , wood left unfinished, inside seems to be unaffected for years and years , save the dust... Put the same wood outside and in months it's gone ..
Logic would dictate the best place to keep any wooden thing is Inside !!! Guessing if you're going to do a Beauty wood job like Rob's , you'd want to build a Garage for it too... Makes Good sense huh!!!
ANYTHING left outside is subject to all manner of Attacks !!! A trailer, "encapsulated" and stored inside , should last a lifetime, and more !!!

[DudKC]

That said, on all my trailer projects, once I have the (bottom) wood encapsulated, I treat it with several coats of a rubberized automotive undercoating material, to provide extra protection.

Great info in this thread, could you elaborate on the products you used before the automotive undercoating material? I am leaning towards using that as the final step in coating the underside of my floor. I am trying to determine which products to use before that. CPES sounds popular but it is very pricey, as you all know.

You know , one thing to consider too is , wood left unfinished, inside seems to be unaffected for years and years , save the dust... Put the same wood outside and in months it's gone ..
Logic would dictate the best place to keep any wooden thing is Inside !!! Guessing if you're going to do a Beauty wood job like Rob's , you'd want to build a Garage for it too... Makes Good sense huh!!!
ANYTHING left outside is subject to all manner of Attacks !!! A trailer, "encapsulated" and stored inside , should last a lifetime, and more !!!

Good tip here. I am just beginning my build and have already called the underground storage facilities in town for pricing. They are temperature and humidity controlled all year. I figure with the amount of work we'll put into this I want it to last a long time.

[GPW]

Just finished the first (soak) coat on my TT repair board and flooring ... Under the fan , the Min seems to evaporate very quickly , leaving the poly to dry ... The fan really speeds things up ... I'm timing it , and will do a "sticky" test and report ... Just FYI

[48Rob]

Gpw,

You may already be aware, but running a fan to help speed the drying process can go wrong if there is too much air movement, resulting in the solvents drying too quickly.
What happens is the paint/varnish can skin over too fast, trapping solvents under that layer that needed to finish evaporating.
When it is just too much, the solvent bursts through the top layer leaving pinholes.

Dud,

I use plain ordinary oil based paint.
I prefer reasonable quality paint, but in an effort to save money usually check the paint stores for mis-tints.
You can get $50-$60 a gallon paint for $5-$10 bucks a gallon.

I mix it well (or have the paint store shake it) pour a quart or so into another container and then thin it down with mineral spirits, usually about 50/50.
The mix doesn't have to be an exact formula, as the consistency will change with temperature.
Thin enough so that it will penetrate easily, but not so thin it drips out of the brush before you can get it on the wood.

As gpw suggests, the first coat (and only the first coat) can be put on pretty heavy as it will really soak in deep, and you want it to do so.
After it dries (the first coat may take 2-3 days depending on temperature and humidity) lightly sand or scuff, or even use a wire brush (lightly) to rough up the surface for the next coat.

After the first coat is dry, you'll notice very hard shiny painted areas, and dull, dry lightly stained areas.
For the second coat, Use fresh full strength paint, and thin it just a bit, around 25% mineral spirits, to allow the mixture to penetrate deeply in any of the softwood areas.
The second mixture will soak into the dull areas, but not the hard shiny ones.

After the second coat is dry (1-2 days) scuff, sand, or otherwise rough up the surface again.
Apply full strength paint.

Allow to dry and then repeat 1-3 more times until there are no areas of wood that do not look like they are completely sealed.

After the final coats are dry, then you can use undercoating or some other product as extra insurance to protect all your hard work.

It should be noted that if you are sealing the bottom of your floor, it should be done before you put the floor on the trailer, as it is far easier to do on a workbench...

It should also be noted that if you don't seal the edges of the plywood, you might as well not bother sealing anything...

When you flip the wood over and bolt it down, you must use care to seal any breaks in your protective finish.
I prefer to drill the holes slightly oversize, blow the dust out, and then use a small brush to apply paint inside the hole.
I'll also put some sealer/caulk in the hole, and on the top and bottom so water can not get in.
And finally, it is always good to seal wood on both sides if possible.
If you're going to use vinyl flooring, the adhesive will serve as a good sealer.

All this is a lot of work, and many will poo poo the idea that it is needed.
It isn't if you're building a low dollar trailer you plan to use for a couple years then throw away, but if you want it to last a lifetime; it requires a little more effort.

I'm not experienced with epoxy, but several here on the board are, and from what I hear, it is a good alternative, though I can't answer any questions about cost or effort required.

Rob

[Rlowell]

All great information. Thank you for your knowledge, experience and willingness to share. That is what makes this web site the best that there is.

My neighbor is just getting hooked after showing him mine. Really, his wife just went over the edge and has started the galley design before visiting this site. Another one bites the dust...good stuff!!

Thank you everyone.

Rod

[GPW]

Rob , ceiling fan on low , just to keep the air moving over it ... 2 hours and it's not tacky anymore , just not dry yet ...

Rio , yeah , these trailers are as addictive as potato chips ...

[GPW]

Here's a pic of the sealing .... you can see how it soaks in ...


Checked and its completely dry now ...

[atahoekid]

Sorry guys, just catching up to this thread. Been away for work. Just to throw my 2 cents in, I plan on sealing my trailer with the poly/varnish mix. I put three coats on some scrap pieces of plywood and lumber and threw the pieces in the backyard for the fall and winter. The scraps are now sitting under about 8 feet of snow, after sitting through a heavy rain season. I plan to start my build in March or April depending on when the snow melts enough for me to drag my frame out from under the snow. Hopefully, the poly/varnish mix holds up to the elements. If it does, I'm going to use that. If not, probably the CPES from the Rotdoctor. I'm keeping my fingers crossed for the poly/varnish mix. It will certainly help the budget I'll post an update when I retrieve those pieces of scrap wood

[DudKC]

I use plain ordinary oil based paint.
I prefer reasonable quality paint, but in an effort to save money usually check the paint stores for mis-tints.
You can get $50-$60 a gallon paint for $5-$10 bucks a gallon.

Rob

Thanks for all the great info, Rob. I haven't used epoxy myself so paint sounds a lot more familiar to me. A couple years ago I painted my basement floor with some oil based paint. It was pretty much like this http://www.lowes.com/pd_46516-4-057.0002000.007_0__?productId=3343608&Ntt=floor+paint&pl=1&currentURL=/pl__0__s%3FNtt%3Dfloor%2Bpaint but it wasn't the Lowe's brand (I think it was Valspar, but this stuff was only $15/gallon). Think this would work, thinned with mineral spirits? If not, what did you use?


Thanks

[WhitneyK]

WOW, what a response!

OK, OK, I too will use the poly / mineral spirit mix. Like I said in my original post, it was just a thought, didn't say it was a good one, LOL.

That's what I like about this site, questions usually get a good response from a multitude of angles.

I drug my donor trailer home from my brothers house up in the hills (had to flip it over upside down and use the front end loader to put it on my good trailer, hasn't been licensed in since '01) Now I get to go from wood to welding. Yee Haw!

[48Rob]

Hi Dustin,

Oil based paint has an average shelf life of 10-15 years, so you should be good to use paint that is just 2 or 3 years old.
As long as this inexpensive paint is being used for sealing the underside of a floor, I wouldn't have a problem using it.

If it were to be used for a standard exterior application (side of a trailer, etc.) I would spend the money and get a much higher grade of paint that has extra pigments and UV protection, so it will last longer/provide better protection.

I'd like to add another tip for the application on the plywood, which is that paints/varnishes are hard to build up to a good thickness on a sharp 90 degree corner, such as is found on a sheet of plywood.
Rounding the edge slightly with a plane, or even some heavy grit sand paper will help insure the sealer doesn't fail on the sharp edge and allow moisture a way in.

Rob

[48Rob]

I plan on sealing my trailer with the poly/varnish mix. I put three coats on some scrap pieces of plywood and lumber and threw the pieces in the backyard for the fall and winter.

Hi Mel,

I'll be interested to see your results!

Three coats sounds a little light, but it may work out for you.
No matter what products you decide to use, complete encapsulation is the key.

Rob

[Dant]

I don't really have a clue about this. I'm adapting a 7' x 10' Continental Cargo Tailwind to my RV purposes. It's finished with 3/8" Luan plywood and I'm thinking of a finish for decorative purposes mainly. I'd considered adding 1/4" cedar t&g, but why add the weight and expense?

After years of struggling with various varnishes and other finishes with my teak trim on my sailboat and teak outdoor furniture, I've decided I like the look and easy application of Watco Teak finish.

Any problem just wiping that on?

I have a little row boat I've built. Captain's varnish looks nice on it. I guess that's an option too. This is strictly an interior finish for my current application. Like your thoughts.

[48Rob]

Dant,

I've been using Watco finishes for many years and am very happy with them.

Their Danish oil finishes work very well for custom colors and color matching.
I've done two trailers now with them, though I have topcoated both with varnish.

The Danish oil finish has a mild colored varnish like quality in that it stains the wood a particular color, soaks in pretty well, and dries to a slightly hard, though not shiny finish.
Similar to a single coat of a hand rubbed varnish.

I used their Teak oil on a customer's wood chest from overseas.
Never did figure out what kind of wood it was, but chose the teak as it is designed to soak into very dense wood that regular stains/finishes have trouble penetrating, such as teak.
I don't believe it contains a hardening agent like the standard Watco finishes, but rather it is more of true oil finish.

For the inside of your cargo conversion, it would work, but will likely scratch/show scratches very easily.
If durability is your goal, a stain and topcoat of something very hard like polyurethane would wear well, though simply wiping on some oil would be a lot easier...

Good luck, and be sure to post some pictures when you get your finish applied!

Rob

[Dant]

Thanks Rob. The thing I like about the oil finish is that it's easy to maintain, as well as apply. I can just put more on over the scratches if it bothers me.

With varnish, eventually it peels; or if you have a scratch, you have to sand well and reapply.

At least that's my thinking. Make sense?