Tips on Varnishing Wooden Boats

Varnishing Tips and Photos by Joel Terbrueggen

When it comes to varnishing there are any number of ways to accomplish it. I do not believe one way is necessarily better than another, it all comes down to whatever technique you are most comfortable with.

After sealing, I use a Scotch Brite pad or 320 grit sandpaper to LIGHTLY remove any large dust particles. I stress LIGHTLY because you do not want to burn thru here. Apply at least three coats of varnish before aggressive sanding.  Sanding can be done in as many ways as there are owners doing the sanding. I prefer dry sanding with 220 to 320 grit.

After about 5 coats I will use a D/A with 320 grit followed with 220 block sanding with the grain to remove the swirl marks that may be visible in the sunlight. This will give you a flat finish as the grain becomes less visible. My final coats (9 to 12+) I use all 320 grit. I say 12+ because I can’t tell you how many times I have had to say the next day “This was my second to last coat”.

During the many sandings you do, there is always a chance of “Burn Thru” in the varnish. An easy trick that usually works is to use a Minwax Satin Marker, Red Oak #215. It looks like a Magic Marker. Just apply to the burn thru area before varnishing. 

Actual varnishing is a personal choice as to application technique: brush it, roll it, or spray it.  I will not say one technique is any better than another. It comes down to which technique you are most comfortable using.

I prefer to roll with a 7″ and/or a 3” roller followed by a 2” or 3″ foam brush to remove the bubbles. This is often referred to as “Roll and Tip”.  By using the roller, a uniform coat of varnish can be applied with less chance of sags and/or runs especially on the sides. The job also goes faster. This is not to say that the Roll and Tip technique is better than other ways, it just works well for me.

I have used different bristle brushes like China, Fox hair, Coyote tail hair (which is extremely hard to get from a Coyote), Squirrel nose hair (another hard one to obtain), etc. but always come back to Roll and Tip with foam rollers and foam brushes.  

Joel Terbrueggen is a member of the Ohio Valley Chapter of ACBS. He has presented many restoration lessons which are available in the Video Library available on our ACBS Members Only site under the Resources tab.  Joel also donated his extensive library of cataloged photos taken as he performed surveys on antique and classic boats over a 16 year period.  These are also in the ACBS Members Only site under the Resources tab.  Joel Terbrueggen currently does much of the wood restoration on boats at the Motor Boat Garage in Cincinnati, Ohio.

Watch for more tips from Joel in the future.