All,
I need your advice here on a couple of matters. First off. I sprayed three coats of shellac over solar-lux analine dye and topped it off with satin poly. The photo shows the resulting mess. There is green blushing all over the place. I haven’t had this problem with my finishing formula, until I sprayed it with an HVLP conversion gun using my compressor. It dawned on me the other day that a considerable amount of moisture starts to come out of the line if the compressor is on a lot. I have moisture filters on the line, however I noticed my local lowes sells a disiccant filter that should be placed at the line just before the spray gun. Has anybody had any problems like this and is a disiccant filter the solution?
SECOND, I’m going to strip the poly off with a chemical stripper and start over. Any advice?
Thanks
Replies
Doug,
It's hard to tell from the pic if the problem was caused by moisture in the air line as it seems to parallel the grain of the wood.
A desiccant filter may or may not help, but IMO, may not be enough if the temp in you compressor tank gets excessive and you do not have a long enough run of galvanized lines of the supply to cool the air and condense out the moisture.
If, (cringe), you simply have a rubber hose running straight off you compressor to the gun, then it's worth a shot, but no guarantee.
Jon
I agree with Jon, it does not look like a moisture type of blush. Rather, it looks like some type of adhesion, incompatability problem. Have you sprayed these materials before sucessfully? Was the shellac dewaxed? Was it fresh? How long did you allow the dye to dry? How long did you allow the shellac to dry?
What was the temperature/humidity?
On another but somewhat related note, it is not a good idea to spray varnish that contains a flattener. When you thin the material, the flatteners tend to rapidly fall out of suspension. This can cause finishing problems like irregular cloudy areas. It's best to spray clear material and then "finish the finish" to whatever sheen you want.
Thanks for your help. I left out one step in the finishing procedure. Between coats two and three of the shellac, I used a glazing stain. At first I surmized that the last coat of shellac lifted the glaze and mixed with it, causing a problem with the poly. I've used this forumula countless times just brushing the products and I have never had a problem. Perhaps the moisture in teh gun, coupled with an with the top layer of shellac mixing with the glaze caused the problem.
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