Finishing question...

[Mike Kolb]

Other than doing spot-repair & touch-ups on structural work, I'm really not experienced with complete instrument refinishing.  As a personal project, I'm doing a nitro lacquer sunburst to a jazz bass (the 3-stringer:)  The color coats are down and 6 coats of clear topcoats are on... after the 6th coat was applied last week, some blushing occurred. It's not major but it's not going away, either.

So my questions would be:

(1). should I expect it to go-away after a leveling-sand, and then proceed with a couple of more coats...paying better attention to the temp/humidity factors?.  

(2). or, will it dissipate on it's own eventually?  

(3). or, would using something like Behlens Blush Eraser be useful, even after a week of curing?

There are some real finish-experts here, and I'd love to hear the thoughts:)    Thanks in advance

[Brady Anderson]

My experience with lacquer blushing is that it never goes away.  The only thing other than starting over that has worked for me is to re-melt the finish with some type of blush Eraser.  Celo-solve has worked for me as well as multiple coats of lacquer retarder sprayed in rapid succession to re-melt the finish.  Frank Ford has posted a good page describing remelting finishes.  You have to melt the finish down to the level of the blush to allow it to evaporate.  Blushing usually occurs from using too thick coats in a rapid drying humid environment.  Add Lacquer retarder to your mix when spraying to prevent this.  Also a good quality thinner helps to prevent this.  Cheap "clean-up" lacquers actually contain very small amounts of water I have heard and should be avoided for mixing with lacquer.

Best

[Mike Kolb]

Thanks Brady... good advice. The blushing is just one coat down (a clear coat) on top of 5 others and the color coats. Since it won't disappear of it's own accord, I'll stop 'wishing it gone':)  

Since it's so near the top, I think the plan might be to leave it all sit for a week, level-sand to the blushed coat, lay-down a few more thin coats, leave it for 2 weeks and wet-sand.  

Thanks for the tip on Franks page... I'll go look right now before doing anything. 

[Mike Kolb]

So there might be another window of opportunity here. In northwest Oregon today, it's supposed to be sunny, relatively warm and dryish.

Could I take a chance on a thin wet coat, in the hopes it would remelt the blushed coat and allow the moisture to evaporate? ... just thinking out loud.

[John Anderson]

If you have an aerosol can of No Blush a mist coat might clear it up.  I always keep one handy and if I see a blush developing a mist coat while the lacquer is still wet over the surface can save the day.  Since your lacquer has cured for a time a mist coat of lacquer thinner with a little retarder in it can work too.  Mist it, let it sit for minute mist it again.  Using too much retarder can leave you with a gooey guitar for days.

[Mike Kolb]

OK, the blushing-bullet has been dodged. Good painting weather today, so I sprayed a light, wet coat outdoors and *poof*, the blushing disappeared.  That was over an hour ago and it's "stayed gone". Back to square one. Whew.

But some lessons were learned, thanks to Brady & John:  watch the humidity, temperature & thickness, and keep a can of NoBlush or BlushEraser handy. I'll be buying a can tomorrow. Thanks for the help. 

[John Anderson]

No Blush is made by Mohawk finishing products.  Probably exactly the same thing as Blush eraser.

[William F.Eden]

Mike if you shoud have this happen in the future just take it in were it is warm and it wiil disappear. I have a little elc. heater with a blower on that I use to warm it up.          But be sure and keep the Insterument at least three feet away and turn it once in awhile Good luck Bill...........