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I agree whole heartedly...at the very least a call to Mohawk is warranted to make sure it's not being caused by a change in formulation of the product...if it is a change then the only solution is to either adapt or change to another product...in this case it would require at the very least thinning of the product and/or use of retarder...

I've never been blessed with a large compressor capable of shooting lacquer straight from the can...I bet it would take a major product change to make blushing occur for me since I already have to thin lacquers by about 40% to shoot them through my system...

I'll stick by my advice to sand it off or at least sand enough off for the blush remover to do the final work...the one time I had severe blushing I rubbed retarder on, sprayed a light mist of straight thinner, and then shot another coat of heavily thinned sealer with retarder...it didn't quite go away, but was surely better...since the problem fell on a piece of furniture and that spot was going to be screwed to a well from the other side of the wall and would be in shadows I left it be...if it had been in the main field of the wet bar I would have been forced to sand it back down and start over and that would have been a severe bummer as during the vinyl sealer application variances in wood tone shot up and I had to learn how to add toner to the product and color those pieces of wood to match the rest...

anyway, yeah obvious issue here that most likely (erm, it is an infinite universe you know) is not in any way the fault of Greg's system and experience

Any chance the moisture is coming from the wood?

No. If the problem was just on the Rosewood I'd say maybe, but the Mahogany neck blank also blushed on the back of the peghead and it's been in my shop for 5 years at 50% RH. No, I'd say this has to do with super fast drying of the product. It was drying so fast that the top half of the back was dry and getting overspray by the time I was spraying the bottom half. I'll be calling Mohawk this morning and I'll report my findings.

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It will probably be alright.

I had some issues with the Behlen/Mohawk vinyl sealer and switched over to shellac for the sealer coat and never used vinyl sealer again. Works great on epoxy pore filler and gives a nice look to the tops.

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

I spoke with Philip at Mohawk- great guy and very helpful. He ran a quality control lookup on the lot # of my can of sealer and the lab said there have been no issues. He said there is a small chance that human error could be involved with not stirring the batch correctly when filling cans and that I might have got a can with too much carrier and not enough solids. He agreed with me that for whatever reason the sealer was drying on my guitar much too quickly. His opinion is that sanding back to level but not into bare wood, applying another mist coat of blush remover, and then proceeding with clear coats will do the trick. He did say however that if any blushing remains after sanding and misting the blush remover, then I'll have to sand more even possibly going back to bare wood and starting over.

He did make a few suggestions. He recommends that I try Mohawk-Finishing Easy Vinyl Sealer 610 series (#550) as he thinks I will like how it flows. Or he suggests thinning the Behlen sealer with a middle range retarder such as MAK. Interestingly, Philip told me that spraying vinyl sealer is NOT necessary for good top coat adhesion, and that the only real reason to spray sealer is for sanding purposes. He said that lacquer will bond to wood just as well as the sealer if a wet coat is applied. He did say that both sealer and lacquer can have adhesion issues if a light coat is applied, such as a wash coat prior to grain fill. He recommends thinning the sealer or lacquer for a wash coat and then spraying a full wet coat at all times.

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It will probably be alright.

Also received this from Stew Mac tech dept:

"Sorry to hear you've encountered some cloudiness in that finish. It sounds like the cloudiness may be a result of concentrated patches of the dissolved vinyl pellets used to make the sealer. Here are some tips for avoiding this:

- Thin the sealer 50:50
- Avoid shaking or excessive stirring of the can. The dissolved vinyl used to make the sealer will accumulate at the bottom of the can so the finish from the very bottom can be cloudy. Shaking the can disperses this all throughout the sealer and can cause cloudiness
-Use a turkey baster or a ladle or mixing cup to transfer the sealer from the can to the spray gun. This way you get the sealer from the top, and not the bottom. Pouring the sealer into the gun will result in sealer from the bottom being mixed in, and can result in cloudiness."

They also have offered to send a new can. I've always had nothing but A+ service from SM. According to this information I have been over-mixing the contents. I always stir the can thoroughly including the sludge from the bottom, mixing well, and then pour into the gun using a paint filter. My thinking is that this is the solids and needs to blended in. My bad. This may be part of the problem, but I've always stirred it this way. And that would not account for the extremely fast dry time.

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It will probably be alright.

That does not sound right to me -- never heard of such a thing, matter of fact our paint repair area at the GM Cadillac plant had racks of paint guns that were continually in motion to keep all the contents in suspension. Over stirring vigorously surely can cause bubbles but every thing in the chemical formula is supposed to dissolved and be spray-able. Wonder what the Mohawk tech's assessment would be?

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Ken Cierp

http://www.kennethmichaelguitars.com/

that really sounds over the top with ignorance...

let's look at this logically:

a can of product contains everything it needs to...in the case of vinyl sealer it's simple chemistry: stir it up to disperse all the material EVENLY...

sounds like you were conversing with a person who needs to clean out their glass belly button (head shoved so far up that the only way they can see is via the glass belly button, and it's obviously dirty)...at best they were confusing vinyl sealer with a satin finish, and in the case of a satin finish you always stir and make sure it stays stirred for an even flat look...too many layers of any flat lacquer will cause cloudiness because the tiny balls of silica create the flat finish by diffusing light as opposed to reflecting it...hence if you are building up a thick finish you use gloss for the build up and flat for the last 2 coats...

anyway, IMO that response from SM was idiotic

I would send the (apparently ridiculous) StewMac response to the Mohawk tech rep and ask him what he thinks.

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Steve Smith
"Music is what feelings sound like"

It doesn't make sense to me either, especially since I have always stirred the sealer thoroughly. I'll ask Philip at Mohawk.

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It will probably be alright.

Talked with Philip again. In a nutshell he said that advice is nuts. He told me that no finish company could put out a product with instructions "be sure not to stir up the sludge in the bottom."

Sanded back the Rosewood guitar at the center of all this, and hit it again with some blush eraser. There are still cloudy areas. I am going to keep sanding and misting until they are all gone or until I hit bare wood, which ever comes first.

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It will probably be alright.

Never heard of a finish you had to "decant" before using. He musta been talking about wine or something.
Whatever!... I'm sure you'll get to the bottom of it. No pun.
Ken

I hope StewMac gets the word that one of their people is putting out bad info.

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Steve Smith
"Music is what feelings sound like"