Teardrops n Tiny Travel Trailers

Like the outside finish I decided I should test the inside finish on some birch plywood as well. I decided on Minwax Helmsman spar urethane, but I was undecided on the the level of gloss and also if I wanted to use Minwax Natural 209 beforehand to bring out the grain. Birch is notorious for blotchy and uneven staining but a light touch with the 209 seemed like a good option. Helmsman over birch seems to be a popular finish around here, so hopefully this will give everyone else out there a good example of what to expect.

Minwax Natural 209


Here is the test panel with just the 209 applied on a couple of the test panels before any poly is added. The 209 has had a full day to dry. The 209 stain is supposedly a clear sealer but does darken the wood slightly. As you can see I am testing two versions of Helmsman, satin on the left, and semi-gloss on the right. Each version of helmsman will be applied to both a panel with 209 stain as well as one with just bare wood, both are sanded to 220 grit.


Inside lighting after 3 coats. Here the satin Helmsman covers both panels, 209 on the left and bare wood on the right.


Same as above but with the semi-gloss version.


Satin in natural light.


Semi-gloss in natural light.


After seeing the outcome I think I am leaning toward the satin without the 209. The poly seems to tint the wood enough, andwith the 209 added, it becomes too dark and and slightly blotchy around the grain.

That's what I did. Helmsman satin finish on Meranti mahogany marine ply and poplar trim without any stain or sealer. Came out fine.

I did end up sanding down and spraying on a few coats of the Helmsman with a Harbor Freight HVLP sprayer which gave a nice even finish. I couldn't get a non-blotchy finish with either bristle or foam brushes where there were overlaps.

_Ryan_ wrote:After seeing the outcome I think I am leaning toward the satin without the 209. The poly seems to tint the wood enough, andwith the 209 added, it becomes too dark and and slightly blotchy around the grain.

Good call
Unless you are lucky or use the "pre-stain treatment", it may or may not get that blotchy look. Final results didn't seem to have any difference in the color of the wood, skip the stain step and get to the satin poly, it does give an amber tint, but I kinda like it. Not that I'm partial to it, but the satin Helmsman is what I used. Doesn't have the glare inside but yet smooth and easy to wipe down when needed.