The Mix??

[campygirl]

We are building our first teardrop. Using a Wyoming Woody as our general guide. I see a lot of references to "The Mix" as a sealant. From what I am gathering, this is Polyurethane mixed with mineral spirits at various dilutions. Is the general idea to use the thinner dilution followed by the more concentrated dilutions? How long do you wait between coats. Is this the same for the drilled holes as it sounds like this is also used as the final coat for the outer skin? Thanks in advance.

[working on it]

* I used the "mix" on my trailer and on a pickup-bed cover system, both with great success. I used Minwax Fast-drying Semi-gloss Oil-based Polyurethane on both projects (done 7 years apart), and also used Kleen-strip paint thinner (mineral oil, the cheap kind).

* Starting with 25%-75% poly-thinner, then 50%-50%, then 75%-25% poly-thinner ratios, I finished with 100% polyurethane before allowing it to cure for a week on the trailer; after that week curing in a garage, I used 2-3 coats of each: oil-based Tractor Supply equipment enamel (sides,front), and silo paint (front slope, roof, and hatch). On the bed cover project, I only waited overnight before painting over the polyurethane with Rustoleum aluminum paint.

* I did both projects contrary to recommendations, using the polyurethane "mix", and the finishing paint applications in direct sun on days well over 100 degrees. Each coat was done as soon as the previous coat had "flashed over", becoming sticky and not entirely dry. There was no sanding done at any time (only pre-wiping dust and/or greasy prints off the wood beforehand). The trailer's wood was ACX 3/4" pre-sanded plywood (phenolic glued-plies), and the exterior was already assembled (doors and hatch were removed for separate handling, reassembled after final painting). The trailer has withstood 8 years of sun and rain, though stored inside 95% of the time. The truck bedcover project used cheap CDX 1/4" and 3/8" exterior grade (since it was an experiment, but worked out well anyway), and turned out as waterproof (after a year outside) as the good stuff (due to the "mix").

painted in heat, lasts 8 years.jpg (107.46 KiB) Viewed 5441 times

bedcover after painting.JPG (122.27 KiB) Viewed 5441 times

[tony.latham]

"The Mix" is good stuff. It's true that it's thinned oil-based polyurethane.

There is no secret ratio. I'll start out with a ball-park 50/50 mix and put as much on as the wood will absorb. It takes much longer to dry because the solvent needs to evaporate. I finish it up with at least one coat of undiluted poly --probably two or three with a light sanding inbetween.

Of course, you'll need to finish your woody off with a spar varnish to protect it from UV rays.

Having said all of that, if I were building a woody, I'd fiberglass/epoxy it and follow that with spar varnish. That'll seal the wood grains with no threat of cracking. Glassing isn't a big deal and it won't inhibit the look of wood.

If you do this, do the walls/doors on the bench and the roof after it's buttoned up.





Food for thought,



Tony

[campygirl]

Thanks! That helps a lot.
It seems like people use it for the screw hole too, before putting the screws in. Is 50:50 the right mix for that. Does it dry in between? Do you have to do multiple coats for that or usually just once?

[working on it]

Thanks! That helps a lot.
It seems like people use it for the screw hole too, before putting the screws in. Is 50:50 the right mix for that. Does it dry in between? Do you have to do multiple coats for that or usually just once?

* I used Loctite PL Premium polyurethane adhesive to join/caulk all joints...and everytime I made a hole, I used PL there, too (easy wat to fill a screw or bolt hole: dip the screw/bolt into a small tub of the PL. then wipe off excess after its in place). I used at least 12 tubes of PL in building the trailer, and probably 5-6 more doing modifications.

[tony.latham]

Thanks! That helps a lot.
It seems like people use it for the screw hole too, before putting the screws in. Is 50:50 the right mix for that. Does it dry in between? Do you have to do multiple coats for that or usually just once?

I’ll put a drop of straight poly in exterior screw holes with a syringe just before inserting the screw.

Tony

[campygirl]

That answers my question. Thanks everyone!