Streaking with Spar Varnish Wipe-On Application

Advice on limiting visible streaks in wiped-on spar varnish finishes. June 28, 2010

I have been using a Spar Varnish mix, per recommendation from Fine Woodworking. Problem: I have streaks in the finish when viewed with raking light. The streaks are with the grain, so I am doing something wrong with application or wiping off, right?

Here’s what I did: I sanded the top prior to adding finish with 400 grit, and it looked great. Denubbed and got all the dust off. I have two coats on now and can see the streaks. Between coats, I have sanded the finish with 600 grit. No gum, all white swarf. Coats consist of 1/3 McClosky's Spar Varnish (Red Can), 1/3 Watco Danish Oil, and 1/3 Turpentine. Any advice on streak removal would be helpful.

Forum Responses
(Finishing Forum)
From contributor W:
Wiping or brushing applications always leave marks. You can minimize the mark by using the right technique of brushing and wiping, but it is rather difficult. Thin your material with longer dry solvent, and brush your material little by little. The best way to get remove the mark is to apply your material by spray.

From contributor M:
For the final coat, after the previous coat(s) are fully dried, cut the formula down (thin) using more solvent than finish to create a thinner quicker drying final coat. Apply to fill in the rub marks and then hand rub out.

Or hand rub out the oil as applied until the finish seems slightly tacky. You will feel your palm heating up as you rub out the finish. If your palm starts to stick to the surface add or prime your hand with a little thinner. Do a test on a scrap piece of wood so you can gain some more experience.

From contributor C:

I too seem to have problems with McCloskeys SV. I've used Absolute Marine Varnish in a wiping mix, and that has worked fine. You might also try a 50/50 mix of varnish and mineral spirits (or turps) and a bit of BLO, and skip the danish oil.

From contributor G:
I've used the Helmsman spar varnish, blo, and low odor mineral spirits. The last of the three is hard on spar. It sets up fast so a quick wipedown after application is necessary. Once it is tacky you should rewet.