I have been working on my bed wood and sideboards. I am using Epifaines High Gloss Spar varnish. I have got seven coats on the bed wood, The boards are laying flat, sanded with 400 wet paper between coats, temperature controlled garage. Have been using Jen foam brushes new one with every coat, varnish not shaken, applied from seperate container. last thee coats have not been thinned. Now here is the problem I seem to be getting little bumps in the finish, almost like large specs of dust. Should I thin the last coat so it sets up faster? Can varnish be cut and buffed like auto paint with say 2000 paper and a polishing compound? The finish looks pretty good now but the wife looked at it and said whats with the little bumps.

 

I can't help you with your questions about the varnish.... but this I know: If your wife noticed it you'd better fix it!!

 

I thought that it was ready to install until she looked at it.

 

Yes, you can sand and hand wax wood finished in varnish.

 

You might see if it's in the can. Try running it through a paint filter (from paint store). Yes, varnish can be polished (look up "French Polish"). You might find a light sand and re-coat to be easier.
You did run a (clean) tack cloth over each coat after sanding, yes?

 

I put 8 coats on all of my stake bed wood similar you what you did, except, I did not thin the varnish at all. I also, after a lot of research used natural hair brushes rather than foam as I was told that the foam could leave 'fur' because the varnish is so heavy. Did you use a good quality Tack cloth before applying each coat?

 

After I wet sanded with 400 I rinsed the wood lots of water, dried, and then tacked before coating. The finish does improve with each coat. I did a test area compairing thinned and straight varnish and foam brush verses china bristle brush, waiting to see how that turns out. I am wondering if my shop heater is just circulating to much dust?
I checked out French Polish, wow that looks like a lot of work for a truck bed.

If you look at where the light is being reflected you can see the bumps in the finish.

 

Well, I think that looks mighty nice.

If it's going to be a show truck, then fix the bumps. Otherwise... it is a truck bed.

 

I do a lot of varnish on my boats. The epiphanes is a relatively thick varnish and it is very slow drying. Slow drying will result in more dust collection. I have to varnish outside on my larger boats. If using the Epiphanes, I have to have the longer days of the spring. I have tried to varnish in the fall and the days are too short, it will blush. I think that you will find that 400 paper is bit fine for varnish work. The number of coats that you are doing is about right. On new or stripped wood I do 10 coats. Filter your varnish before using. I have tried a badger hair brush but went back to foam.
You might consider a faster drying varnish for a topcoat. Varnish will drive you crazy sometimes!
You definitely do not want to leave the truck outside regularly. I say that horizontal+varnish+ teak+ sun is mission impossible!

 

If you have that many coats on you should have no problem wet sanding them down to 8000 - 12000 grit then apply wax . That will give you a nice show finish . My son Ian is going to use oil on the bed boards in his truck so it is easily maintainable . I will use black paint like the factory did .

 

You are right about Epifaines it does take for ever to dry, it can still be tacky 10 hours after application. What would you recomend as a quick dry top coat?

I just put on coat 8. Did things a little different this time. Sanded a little more than usual, flushed the wood with clean water, not from a bucket, strained the varnish and turned off the Hot Dawg heater and then got out of the shop so that I don't make any more dust. Let you know how it turns out in the morning. Thanks everyone for your help.

 

I have used Interlux Schooner over Epifanes, but not Schooner Gold. Schooner gold is a high build slow dry.

 

i would consider warming up the shop above ideal temp and then shutting off the heat a hour before you want to varnish if you can do that without the temp dropping too fast. i agree with others, a quicker drying coat (even a thinned version of your current varnish) should get you set up quickly. careful sand, wipe (maybe with mineral spirits?) then tack cloth. good look, looking very nice.

 

Over the years I have found that a foam brush tends to make bubbles as you use it. Personally I just use them for staining.Being that your varnish is fairly thick it makes me think your bubbles are not able to pop,thus showing up when the coat has dried.It could also be what I call gassing.That is where the solvents in the previous coat haven't had a chance to get out .How long are you waiting between coats?I usually wait at least a day between coats when using waterbased polys,and even 2 days with oil or solvent based products.Maybe you could try and spray it with a cup gun like the ones Wagner makes.Iv'e used them before,they are pretty handy for some stuff.I use a Wagner airless paint sprayer myself.As the other fellas said,filter your materials, use a tack cloth and don't raise any dust if possible. By the way,the bed looks really nice.

 

If you still have the bumps then I would suggest that you skip the rinsing with water. The varnish dust that is left after sanding will blend right back into wet varnish anyway - it doesn't have to be removed. If I was doing it I would blow off with air and lightly wipe with a lint free cloth or a tack cloth but not use any water. If you were to look at your 8 coats of varnish under a microscope you would see a surface that looks like a sponge. Even though the holes are very small they are enough to hold minute amounts of the water you are using to wipe the dust. They won't dry easily so I think the bumps you are getting is from them gassing and causing the next coat of varnish to bump up.