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Help with runs, varnish over epoxy

PostPosted: Sun Jul 05, 2009 8:13 am
by nevadatear
Our woody build is almost finished. I am applying varnish over epoxy. the roof and hatch look great, but I keep getting runs in the sides. I tried thinning, applying with smooth foam roller, tipping off with dry foam brush,being very careful, not overworking but.... I thougt it looked great yesterday morning, came back last night and one side looked awful. Runs AND orange peel. The expoy is sanded very smooth, so I know it is not the base. The runs/drips are off the vertical surfaces of couse. Any hints?

Debbie

PostPosted: Sun Jul 05, 2009 9:43 am
by Juneaudave
Bummer...I know this is going to sound just plain wrong..but I think you need thinner coats. Here's how I varnish on my boats, maybe there is a clue here that will help....

First..with varnish, I wet sand lightly w/ 220 grit between each coat to remove dust nibs. You will probably want to go ahead and remove the runs at this point on your project. BTW...I don't skimp on varnish and get a good marine spar like Epiphanes, Interlux Schooner, etc. I think it pays in protection to the epoxy and durability over time.

Wet down the floor with a misting bottle if you are getting a lot of dust. In addition dampening anything lying around, I think wetting the floor helps with the static electricty. It seems like fresh varnish is like a magnet.

Strain your varnish into a separate container... and never dip your brush into a can or put leftovers back into the can. Seal the can good.

Use a foam brush to apply the varnish. use long strokes with a crossing pattern and don't overwork. This should leave a light coat that should not run at all.

Let dry, then repeat three or more coats, wet sanding in between. The more coats you put on, the deeper the finish will be and more protection you will give your epoxy. I ususally put about 6 coats on new work.

Hope I mentioned suomething that helps...

:thumbsup:

PostPosted: Sun Jul 05, 2009 10:51 am
by nevadatear
Thanks, Dave, I am going to give that a try. After reading your post, I think my problem is I have been trying to use the roller on the sides as well as the top. When I used the brush on the doors before install, I didn't thin it out and got brush marks, so (after sanding my life away to remove the bad finish), I will thin out the varnish more and use just the foam brush on the sides, but stick with the roller on top where I can't reach and it has been doing a good job. Appreciate your help, can't stop looking at your tear, it is gorgeoussssss! I forgot about straining the varnish, I learned that years ago at my Dad's knee, he made roulette wheels and I grew up in his shop, but I can't get the finish he used to. But, then again he used lacquer and had a spray booth!

A thought

PostPosted: Sun Jul 05, 2009 10:54 am
by eamarquardt
Maybe you could put some supports under one side of the frame and jack up the other side so you "heel" your teardrop over a bit (we're using varnish (a nautical finish) so nautical terms seem to be in order. Then varnish the windward side which is a little more horizontal and let it dry. Then reverse tacks, and do the new windward side. Mabye heeling the tear over a bit will give you the "edge" that you need to get a run free finish.

Hope this helps.

Cheers,

Gus

PostPosted: Sun Jul 05, 2009 10:55 am
by madjack
I'm with Dave on this...if you are getting "sags" and "orange peel" AFTER you think your done, then odds are, you still have the varnish too thick...onna vertical surface, you need to put so little at a time, it BARELY wets out the surface...thin is the key...orange peel can also be caused by environmental factors such as too much dust in the air or even too high a humidity...amongst other things................
madjack 8)

PostPosted: Sun Jul 05, 2009 11:00 am
by nevadatear
Thanks, madjack, I think you are probably right. I thinned it, but obviously not enough. That is more likely than humidity here in the Nevada desert. Although dust could certainly be part of the problem, although I would have expected it to impair the roof more than the sides, and the roof is like glass.

PostPosted: Sun Jul 05, 2009 11:11 am
by madjack
Randy, you are probably correct about the humidity...and yes, the dust should have affected the top more...SOOOO, that leaves thinning your application of varnish...try a coat...a coat so thin, it appears you are wasting your time and see how it comes out...
madjack 8)

p.s. I wonder now, if hi heat and low humidity may be causing the surface of the varnish to "flash" over too quickly, trapping still wet varnish underneath it, resulting in the sagging your are experiencing...I dunno, just thinking out loud...I still think thin will getcha in............MJ

p.s.s. what didja thin it with..................MJ

PostPosted: Sun Jul 05, 2009 5:25 pm
by S. Heisley
...About what MJ said:
. I wonder now, if hi heat and low humidity may be causing the surface of the varnish to "flash" over too quickly, trapping still wet varnish underneath it, resulting in the sagging your are experiencing...I dunno, just thinking out loud...I still think thin will getcha in............MJ


...How about a poor man's humidifier for the garage? (Use a full bucket of water in front of the bottom blade area of a fan, blowing on the lowest speed.)

Just a thought.... :thinking:

PostPosted: Sun Jul 05, 2009 7:18 pm
by nevadatear
madjack wrote:Randy,

p.s.s. what didja thin it with..................MJ


Thinned with mineral spirits. Oh, and by the way it is Debbie posting right now. Randy's the builder, but I am the finisher.

debbie

PostPosted: Sun Jul 05, 2009 7:34 pm
by madjack
:oops: oopppppses...my apologies...mineral spirits should work fine...it is what I usually use...a thought though...I usually thin 10-15% when SPRAYING...I don't usually thin when using brushes of rollers :thinking:
madjack

PostPosted: Mon Jul 06, 2009 1:03 am
by Mauleskinner
madjack wrote:..a thought though...I usually thin 10-15% when SPRAYING...I don't usually thin when using brushes of rollers :thinking:
madjack

I was gonna say that! :x

Definitely, though, try it full-strength. You want a thin coat of varnish, not a coat of thin varnish.

PostPosted: Tue Jul 14, 2009 5:49 pm
by Lesbest
When varnishing my boat , I would thin the varnish for the first 2 coats, and use full strength for the next 3 coats. Putting the varnish in a bucket of ice to cool it causes it to thicken a little so you build thickness faster AND the varnish hardens from the inside out. The hotter the weather the better this works.

Sand in the evening and varnish early in the morning when the air is still.
Make sure there is no dust on the floor (wet it down) and keep your surface dry so you don't get bubbles as the moisture evap. and tries to get thru the varnish.

Dip the brush in the cool can but wipe into a clean can so the bubbles don't come off the brush into your finish.

Chris Craft used 3 coats on all production boats--those going to shows got 4. Now for that deep down smooth finish it takes up to 15 coats, sanding with 2000 grit before the last 2.

The sun and weather will erode up to 2 coats a year, so it is an ongoing process.

Hope this helps, Les