Please HELP!

[pilot2222]

I have experienced blushing during the application of the sanding sealer on the guitar I am finishing.  Because I am an amateur, I kept adding additional coats of sanding sealer after I first noticed the "haze".  My thought was that additional coats would burn into the previous coats and make everything alright.  After 8 coats of sealer I sanded the surface thinking that maybe while I am leveling the surface the haze might go away.  Fail!  I sanded away most of the hazy clouds but what I am left with is a smear type of look and white specs within the pores of the grain!!! 

Mahogany body is what I am working with.  After sanding with 220 grit sandpaper I tried adding clear grain filler to get rid of the haze.  Fail!

Since I did not follow the correct action, which is immediately apply blush eraser, am I screwed?  I about ready to call it quits by either continuing with the sanding sealer process with the flaw or spray painting over the sanding sealer with a solid color. 

PLEASE HELP!!!

 

[tfarny]

I'm no expert, but I'm pretty sure you'll need to say exactly what products (brands) you used and what exact application method, before the real experts can help you.

 

[pilot2222]

Sure.

Mahogany body, StewMac waterbase grain filler (clear), deft sanding sealer. 

 

[jackthehack]

Sounds like either you didn't allow the grain filler to completely dry out before you started shooting the sanding sealer and/or you're shooting the sealer too close to the body/not applying thin enough coats. If you attempt to shoot sealer or lacquer when conditions are too humid, that can also cause problems like this.

"I sanded away most of the hazy clouds but what I am left with is a smear type of look and white specs within the pores of the grain!!! "

Sounds like you tried level sanding it back before it was completely dry.

Hate to say it, but you're probably going to need to sand back down to wood and start over....

 

[jackthehack]

By sanding back down to wood, I meant starting over with the sealer; the pores should remain filled and you shouldn't need to refill...

 

[pilot2222]

Eureka!  I sanded back the grain filler & sealer via wetsanding with 220 grit and it worked!  :icon_thumright:  The water helped clean out the pores where the haze was hanging out.  I will finish the wetsanding tonight.  Let it dry and then hit with a coat of sanding sealer for an overnight resting period.  Thank you for the advice, everyone.  I should be back on track by tomorrow.  :rock-on:

 

[-CB-]

Hate to say it, but you're probably going to need to sand back down to wood and start over....

Everything Jack said - but I want to expound a bit on what's quoted, above.

You could sand it back.  I see you did a lot of sanding, and it all worked out for you, but here are some alternatives to try (the next time!)

First thing, you were more or less correct that adding sealer would eliminate blush - IF - you got the piece into a very dry climate to do so.  Adding more sealer or lacquer in the same humid climate only compounds the issue.  Many times, blush goes away by itself after a while - or you can drive it out with moderate heat (hair drier).

Lets say you got dried-in blush.  What to do.  On seal coats, you can reapply, use blush remover, or drive it out.  You're sanding too early got a mess.  Okay... then you can whats known as "amalgamator" to reflow the surface.  That would have 100 percent cured your white pores in the wood.  After that, just sand and level normally.  Amalgamator takes a long time to dry and will cure many issues with lacquer.  Its basically a reflow/slow driy solvent that remelts and reflows lacquer thats already applied.  In your case, a start over quick step would have been to wash the piece in acetone.  Acetone melts lacquer like crazy, but is very fast dry.  A rag with acetone would clean out the old sealer, and remelt whats in the pores.  You might have had to do a bit of a "rinse" with acetone, keep an area a little wet if the pores were deep and the whiteness continued.

I'm all for the reduction of lots of sanding.  Elbow grease is a precious item!~ Letting chemistry do the work is a good thing.

Not a self promotion - but a credit to many folks here - there is a collected knowledge and experience base here that is very hard to find and tap into in other places.  There are some specialized web-forums that mostly deal with the product of the folks who sponsor the forum.  Thats great, but it limits your information and experience if you're not using that particular product.  I'm amazed at all the information you can get here.... just blows me away.

Another place - go over to Frank Ford's www.frets.com  and read up in the luthier section.  You wanna see terrible made right?  You wanna see the finishes from hell?  Franks been there, done that.  He's mostly acoustic instruments (high end at that), but everything he has there also applies to our solid bodies.

Carry on, troops....!~

 

[big bob]

Eureka!  I sanded back the grain filler & sealer via wetsanding with 220 grit and it worked!   :icon_thumright:  The water helped clean out the pores where the haze was hanging out.  I will finish the wetsanding tonight.  Let it dry and then hit with a coat of sanding sealer for an overnight resting period.  Thank you for the advice, everyone.  I should be back on track by tomorrow.   :rock-on:

Don't wet sand with water, if it get into the wood any ware the wood will expand and you could have problems, I sand with naphtha, mineral spirits, gamisol, if any of these get into the wood they will not cause it to expand.
great to hear you fixed the problem

 

[tfarny]

You're wet sanding with water and spraying the next day? Seems like you're asking for finishing probs forever that way. That wood needs to be dry, dry dry.

 

[Keyser Soze]

Another tip.  If you are spraying with rattle cans in a humid environment pre-warm the cans by placing them in a bath of warm water prior to applciation then try to finish/pause your application before the can becomes noticeably cooler.

The pressure released from the can causes the contents of the can to become colder, this is somewhat unavoidable, but by minimizing the temperature differential between the moisture in the air (humidity) and the aerosolized finish you minimize the amount of condensation caught up in the finish (a major source of blushing.)

 

[pilot2222]

Thank you so much for everyone's advice.  I definetly know what to do next time.  Much to the dismay of some I began wetsanding the body with 220 grit sandpaper on Friday.  I completed the process on Saturday morning.  This took off all of the sanding sealer and all of the haze that I had on the back of the guitar.  I let it dry for an hour and I wiped the guitar down with naptha to clean out the pores as much as possible then I let it sit for another hour. 

Here is the cringe part for some of you, I used a tack cloth to make sure there was no dust on the guitar then I hit with a VERY light coat of sanding sealer.  I let it sit for three hours and then I hit it with one more VERY light coat of sanding sealer.  I let it sit overnight.  On Sunday morning I didn't want to rush it so I let the humidity come down (I'm learning) and then I sprayed two more regular coats of sanding sealer on Sunday afternoon.  It felt a little sticky yesterday evening so I decided to call it a day.  I will pick up the additional coats this afternoon.

By the way, it looks great!  As soon as I'm done with sanding sealer process then I will post pics.