How do I proceed - Bad Orange Peel on Shellac

OK, I'm back to working on FINALLY completing the top of the drafting table. As several of you may remember, I put it aside after unsuccessfully trying to rub out the Waterlox finish I put on it. Witness marks everywhere, so I put it down for awhile and built a serious spray booth.

So my setup is now a spray booth with an explosion-proof fan that can accommodate the large table top. (Pretty awesome setup. I need to get it published in a magazine.)

My game plan was to spray on a couple of coats of 1.5# cut shellac as an intermediate layer, then top coat with Target Coatings EM6000. A few coats of that, time to cure, rub it out, and finally install the top.

Well, hadn't used the HVLP system in a few months (and never used it with shellac) and I got the worst case of orange peel you can imagine. I couldn't figure out how to make it go away, so I've been sanding it off (that shellac is tough stuff to sand. Never realized).

I think I'm left with a very thin coat of shellac over whatever remaining coats of Waterlox are there.

How to best proceed?

1.) Spray a barrier coat of dewaxed shellac (but this time not screw it up).
2.) Just go ahead and spray several coats of EM6000.

Any other approaches?

Was the shellac even necessary? The last coat of Waterlox was wiped on on May 6th, so it's had 10 weeks to cure.

Orange peel happens if you get too close and spray a little too thick. Shellac is easy to sand, but thick shellac is harder to sand.

I feel for you. I have been there too. If it were me, I would level the surface again, sand thru 400 and wipe on a couple waterloo coats. Skip the spray skip the target skip the Sheila, skip the rub out. If you wipe on thin, there will be negligible dust that accumulates.

Get a bunch of rags and a gallon of denatured alcohol.
Wet a rag with the DNA and wipe the shellac off.
Go in the direction of the grain.

Once you've removed the majority of the unevenness, sand with 220 grit.
BTW- if you can lay your hands on some garnet sandpaper - the reddish brown colored sandpaper - that's the stuff you want to use for what you're doing.

Been there/done that (getting rid of a rogue coat of shellac)..... more times than I care to remember....It's a stinky, stickey, nasty job made doubly miserable by the heat and humidity..
I strongly recommend doing it outside in the shade and sheltered from any wind as much as possible. Your going to be putting out a lot of fumes w/the wiping down part & the wind and Sunlight will make the DNA evaporate too fast. The humidity will slow down the evaporation however and allow the DNA to do it's job better.

The good news is that no power equipment is involved/unlike all my past experience, you're doing this for yourself - I was always on the clock and couldn;t indulge.......ice down a 12 pack and dip into it often..

Quote:

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Originally Posted by Prashun Patel

Orange peel happens if you get too close and spray a little too thick. Shellac is easy to sand, but thick shellac is harder to sand.

I feel for you. I have been there too. If it were me, I would level the surface again, sand thru 400 and wipe on a couple waterloo coats. Skip the spray skip the target skip the Sheila, skip the rub out. If you wipe on thin, there will be negligible dust that accumulates.

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The rub out is a feel and glossiness thing. My wife wants a semi-gloss surface, with that nice feel.

I've demonstrated that I'm unable to rub out Waterlox adequately, so that's not an option. As beautiful as the Waterlox looks just wiped on, it's too glossy for her tastes. That's why I'm heading in the Target EM6000 / rub out direction.

I've thought of the rags / DNA approach. When I tried it on small spots I got a gummy mess. Even harder to sand off. I'd imagine that if I skip the chemical mask I could also skip the 12-pack ;) Actually, I can do it in the spray booth and just exhaust the fumes. And with my new cool booth, I won't blow up doing it.

I still have the question as to whether I need a shellac coat between my cured Waterlox and EM6000.

Your finished job will never be any better the the undercoat or the under surface.

I would suggest that your first steps should be to get some corrugated cardboard boxes and practice lay down good coats of finish. It would also be good to buy Charron's Spray Finishing (Amazon will have it) and work your way through it. It will tell you how to set up and use your equipment as well as showing you how to spray and adjust your spray for the best finish. There is quite a bit more to spraying than just filling up the gun and pulling the trigger.

Let me make a couple of comments. First, Waterlox must be allowed to cure for 5-6 weeks before you can rub it out properly. It's a slow curing finish.

Second, shellac is normally sprayed at not above a 1# cut. It should be applied very thinnly--it's not a finish that can be "built up". It can also be sensitive to the temperature.

Thanks, Howard. Didn't know about the 1# cut. Glad I didn't try it at a 2# cut.

The Waterlox was cured for a month before each attempt at rubbing out. That's more than the 3 weeks that the company suggests. No matter, I've demonstrated multiple times that I can't rub it out without generating witness marks. Don't want to beat a dead horse on this one - it just doesn't work in my hands. Anyone who gets it to work, my hat is off to you. I'm sure it looks awesome. I just can't do it.

How long do I have to wait to sand a sprayed on shellac coat?

I've sprayed a few coats on this morning. They look much better, but they didn't smooth out the remaining orange peel that I couldn't sand out from yesterday, so there is still more sanding in my future. My biggest problem in spraying the shellac was in using too big a nozzle on my gun. It sprays well with a #3 tip, but not with a #4 tip with my Fuji gun.