Lacquer issues, time to sit down with the gurus..

[LtDave32]

Oh, venerated ones.. Burn the incense and sound the gong.

I must humble myself before your presence. Pass the peace pipe and play the pan flute music. I seek knowledge.

The paramaters:

Tomorrow; High of 57 degrees. No better (drier) than 60% humidity at best, at peak temp. Low of 38 or lower. We're talking a shoot at 1:30 PM, maybe 2:00

I live in the Calif desert. There IS no humidity. -But not this time. Record wet for this year, record humidity. Not normal.

I have a job to get out and done. I have to spray. I have found that my lacquer does not behave below 58 degrees or so. I will get blush. Do not want blush. I have no retarder. I can't get retarder. I live in a barren land where they do not know about such things. Everything is a long drive or mail order.

That leaves me stuck with what I have; lacquer and thinner, and a lot of it.

I have never done this, but have been recommended to do so by a knowledgeable friend:

Warm a jar of lacquer in a double-boiler on the stove.

Sounds scary. Do not want explosion. Just want warm lacquer.

sound feasable? Break me off a chunk of advice here..

 

[Barnaby]

I'm no guru, but do my wax potting on a portable gas burner outside. I'd never do it on the stove in my house, and nitro would surely be worse. Do you have something that can be used outside like that? Maybe an electrical plate instead?

That being said, it doesn't sound like the safest course to me, but bow to the knowledgable in this regard. I'm also curious to hear the answer.

 

[LtDave32]

I'm no guru

Oh yes you are. If ANYBODY is a guru on this forum, it's you. You and all your hand tools and all.

I bet there's a flute soundtrack when you work.

, but do my wax potting on a portable gas burner outside. I'd never do it on the stove in my house, and nitro would surely be worse. Do you have something that can be used outside like that? Maybe an electrical plate instead?

That being said, it doesn't sound like the safest course to me, but bow to the knowledgable in this regard. I'm also curious to hear the answer.

Yeah, Barn.. I've got something like that. Camp stove.

It's the danger aspect that has me concerned. I don't want trouble. Willing to work outside.

What about setting a mason jar of lacquer (lid on) in a pan of boiling water, off the heat, and just letting the hot water warm the lacquer?

 

[edro]

How about this, heat water inside, fill thermos bottles... Use an old ice chest with drain hole out on porch or somewhere... Water cools, drain and dump another thermos of hot, close lid back...

 

[LtDave32]

How about this, heat water inside, fill thermos bottles... Use an old ice chest with drain hole out on porch or somewhere... Water cools, drain and dump another thermos of hot, close lid back...

That's a little involved. I just want to warm my dang lacquer..

 

[edro]

Maybe so....but we won't read about you in the newspaper...

 

[Barnaby]

Oh yes you are. If ANYBODY is a guru on this forum, it's you. You and all your hand tools and all.

I bet there's a flute soundtrack when you work.

Something like this?

Yeah, Barn.. I've got something like that. Camp stove.

It's the danger aspect that has me concerned. I don't want trouble. Willing to work outside.

What about setting a mason jar of lacquer (lid on) in a pan of boiling water, off the heat, and just letting the hot water warm the lacquer?

Gotta say, the idea of nitro near an open flame is worrying the more I think about it. Option 2 might be much safer. Electric baby bottle warmer? Crock pot?

 

[LtDave32]

More like this:

[ame=http://www.youtube.com/watch?v=NE6SEdnVUh4]Kung Fu[/ame]

 

[ARandall]

The problem with just warming the lacquer is that EVERYTHING else is a bit cold.....the gun, the air and also the guitar surface itself. If you can manage to keep the gun warm, as well as maybe gently warming the guitar too then you can allow it to flow in most aspects.

edit - do you have a glue pot to warm the lacquer??? or even boiling the kettle a few times and surrounding the lacquer tin with hot water.

 

[LtDave32]

The problem with just warming the lacquer is that EVERYTHING else is a bit cold.....the gun, the air and also the guitar surface itself. If you can manage to keep the gun warm, as well as maybe gently warming the guitar too then you can allow it to flow in most aspects.

edit - do you have a glue pot to warm the lacquer??? or even boiling the kettle a few times and surrounding the lacquer tin with hot water.

I"m going to keep the guitar body in the house, near the heater, until spray time. I don't have a glue pot, but supplementing the water surrounding the mason jar with fresh hot water from the teapot is a good idea.

Immediately after spraying, it gets set in the house.

 

[Roman]

Dave, I'm way north of you and it has been raining for a month now. One day of sunshine is all I have seen.

Anyway........I'm still spraying, got no choice. Here is my method.

Warm up the lacquer
Warm up the spray area as best I can.

98% humidity be damned! Start spraying...........wet coats too!

Blush???? no big deal. Get out the hairdryer. Just like magic you watch that cloudy grey turn crystal clear.

Move the guitar over to the "special drying section"

It is simply a bench where I have strategically placed lamps with 75watt bulbs helping along the cure.

The only downsides are you cannot get that 3 or more coats a day in....2 if I push it. The other one is that I can only do a top and sides or back and sides.

If I built a cure room with the lamps in it It could be hung.

Heat is your friend.


Edit: I'm using segrave with no retarder. Normally I run 50/50, but I upped the thinner to about 60% and have no problem with it flowing in the cold. The temps are about the same as in your neck of the woods (desert)

Second edit: You got a hairdryer?? heat gun?? Metal cup on your gun or plastic?? I just hit the cup with some heat (low) to get it warmed up ....Not too much and not too fast. get the cup warm to the touch.........start shooting. A metal cup will retain the heat longer.


Edit three after reading the other posts:

I heat the guitar body as well with the heat gun. This way I have both lacquer AND the surface where it is destined warm

 

[Open_Book]

It's the danger aspect that has me concerned. I don't want trouble. Willing to work outside.

What about setting a mason jar of lacquer (lid on) in a pan of boiling water, off the heat, and just letting the hot water warm the lacquer?

Please dont! Those jars aren't even close to heat-safe Pyrex types - and even with one of those I wouldn't keep a lid on it.

 

[LtDave32]

Dave, I'm way north of you and it has been raining for a month now. One day of sunshine is all I have seen.

Anyway........I'm still spraying, got no choice. Here is my method.

Warm up the lacquer
Warm up the spray area as best I can.

98% humidity be damned! Start spraying...........wet coats too!

Blush???? no big deal. Get out the hairdryer. Just like magic you watch that cloudy grey turn crystal clear.

Move the guitar over to the "special drying section"

It is simply a bench where I have strategically placed lamps with 75watt bulbs helping along the cure.

The only downsides are you cannot get that 3 or more coats a day in....2 if I push it. The other one is that I can only do a top and sides or back and sides.

If I built a cure room with the lamps in it It could be hung.

Heat is your friend.


Edit: I'm using segrave with no retarder. Normally I run 50/50, but I upped the thinner to about 60% and have no problem with it flowing in the cold. The temps are about the same as in your neck of the woods (desert)

Second edit: You got a hairdryer?? heat gun?? Metal cup on your gun or plastic?? I just hit the cup with some heat (low) to get it warmed up ....Not too much and not too fast. get the cup warm to the touch.........start shooting. A metal cup will retain the heat longer.


Edit three after reading the other posts:

I heat the guitar body as well with the heat gun. This way I have both lacquer AND the surface where it is destined warm

Roman, that was awesome. Thank you!

I'm running Cardinal 2000 that's 50/50. I'll add a touch of thinner to get to 60%

Metal cup, 32 oz. Yep, I have a hairdryer. And a red heat lamp.

Open Book, I'm not talking about putting the jar under direct heat, simply hot water around it. I"m switching to the gun cup (aluminum) anyway.

 

[Open_Book]

Hot water, glass jar with a lid on it = not good. Don't ask me how I know...

 

[Freddy G]

Roman's advice is solid.

I keep everything inside at room temperature until it's time to spray. Then just like Roman I have an area that is heated with lamps for dry time.

 

[emoney]

Humidity at 65% he says? BUWAHAHAHAHA!!!! What sissies you guys are!

Real men spray lacquer at 100% humidity, WHILE, sweating profusely with an
inside temp of 102 degrees AND wearing wool socks.

Oh..and you can pick up a single burner "hot plate" at a discount store for like $10.00. Perfect
to have laying around the shop, along with a discarded stock pot the spouse no longer wishes
to use. Fill it halfway with water, put the lacquer in one of those canning jars and let it stew a bit.

 

[David Collins]

Roman's tips are spot on - high humidity need not be much concern if you can provide a warmed drying room.

I'm not convinced that heating the lacquer itself will help much here though. The typical approach for eliminating blush is to use a lacquer retarder (typically butylcellusolve) which gasses of slower. This way moisture captured from the air while spraying is allowed more time to evaporate from the finish before the finish hardens and traps bound moisture inside.

I've used heated lacquer quite a bit, from quart guns on a low-temp warming block (sealed / explosion-proof, never a flame heater or unprotected heating element) to pressurized heated circulating systems straight from a drum. The goal here though is to further thin the lacquer viscosity without lowering the solid content, but this has exactly the opposite effect of blush reducers. Heated lacquer will set and harden faster, potentially trapping more moisture inside as opposed to slowing the cure to allow more time for moisture to escape before setting.

Heated lacquer is great for many reasons, but I don't know that it would help much with blushing concerns (and comes with great safety risks if you don't have proper heating equipment). Of course I wouldn't want to spray with the lacquer cold, but if you keep your gun/pot in a warm room until right before you take it out to spray I wouldn't feel compelled to warm it any more directly.

I would thin it a bit more than usual, using the lowest volitility (slowest to gas off) thinner you have available. Then take it to a warm during room immediately after spraying, and this should lower the RH down to a comfortable level to allow curing without blush. If your air is 60% humidity at 57°, if you can bring it in to a room that's a modest 75° the humidity will be dropped down in to the 30's.

 

[H.E.L.Shane]

Edit: I'm using segrave with no retarder. Normally I run 50/50, but I upped the thinner to about 60% and have no problem with it flowing in the cold. The temps are about the same as in your neck of the woods (desert)

Second edit: You got a hairdryer?? heat gun?? Metal cup on your gun or plastic?? I just hit the cup with some heat (low) to get it warmed up ....Not too much and not too fast. get the cup warm to the touch.........start shooting. A metal cup will retain the heat longer.

temps here are crappy too even though my shop is heated.. I can't afford to keep it in the mid 70's all the time, so it drops to the 50's at night... which leads to thick, cold lacquer


I use... drum roll.... Red Chicken Brooder lamps i get at Ag-Way or tractor supply!!!! I hang the guitar and put the lamp about 18" from the guitar so that the surface temp doesn't get past about 90 degrees... rotate the guitar twice a day.. (i got a laser thermometer off ebay for 20 bucks... reads the same temps as the $100 one I borrowed from my old work!)

I use one to keep the lacquer and gun warm as well. i have it shining on the paint shelf and turn it on about an hour before i start spraying.. its a bit further away. maybe 24 inches?? , I try to keep that area about 75 degrees max, don't wanna have an explosion!!!! I turn it on when i first get into the shop and within about an hour, every thing is good ta go.

And I used to use Seagrave too... but have switched to the Mohawk Piano Lacquer since they reformulated it to eliminate the recoat window... after a gallon sprayed, my opinion is that it is 95% or better the same as the seagrave!!!!! (the spec sheet is almost identical...)

I used seagrave for the past two years, but the price kept going up and up and started to look for an alternative. At 35 bux a gallon... you might want to give it a shot!

Thankfully, Humidity hasn;t been an issue in the winter, but last summer... OMG.. it was HORRID.. there were WEEKS that i couldn't spray without blushing (for a myriad of reasons).. and the old hair dryer got a workout!!!

 

[mlp-mx6]

Do what Roman said. BOILING water? Are you kidding? You want it *warm*, not hot. Hair dryer or heat gun (on low) should do fine. I would suggest being careful with forced-air drying on wet coats. You could force solvent bubbles in the curing lacquer by having the surface "skin over", thus trapping more solvent underneath, which could bubble with any additional heat (light bulbs). (DAMHIK)

 

[Skyjerk]

Warm a jar of lacquer in a double-boiler on the stove.

Sounds scary. Do not want explosion. Just want warm lacquer.

sound feasable? Break me off a chunk of advice here..

what if you warmed it with tap water?

Put the jar in a pan in the sink, obviously a pan thats shorter than the jar. Let the
hot tap water run slowly through the pan keep the water running slowly once the pan is full. It'll spill out the top but should be easily able to keep the water hot enough for long enough to warm your lacquer and you'll have no heat source to potentially cause ignition and it wont be hot enough, fast enough to risk cracking the jar

Letting the water run slowly should allow your water system to keep up without using up all your hot water.

with a jar like a mason jar it shouldnt take that long...