# Blotchy Lacquer



## buzzy (Aug 2, 2009)

Hi! I just finished building a cabinet for a subwoofer. I have problems in finishing the cabinet. I have a bubinga veneer on the cabinet. I applied lacquer to it and I have lots of blotchy patches. The picture below show the kind of blotches I have. 


















The dull spots are the parts where the lacquer will not stick to. I don't know if this a fish eye problem. The place where i live does not sell fish eye eliminator. Is there any other way to solve this problem ? Should i try a coat of shellac on top of this damaged lacquer coat ? 

Maybe what i have done so far may help in identifying my problem.I shall list what i have done.

1. I sanded the raw bubinga veneer with 240 grit sandpaper.
2. I put a coat of wood stain diluted with thinner.
3. Then i put a few coat of lacquer. ( This coat did not have much blotchy problem). 
4. Then i sanded the fully dried lacquer coat ( abt 1 week of curing) with 360grit sandpaper. Then 600 grit. 
5. After sanding i applied another coat of lacquer. This is when the blotchy spots appear. Spots where the lacquer will not stick to.


I am in desperate need of help. Any help appreciated. Thank you.


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## Rick Mosher (Feb 26, 2009)

> I put a coat of wood stain diluted with thinner.


There is a LOT of wiggle room in that statement! It may help to know what kind of stain and solvent. There is definitely an adhesion issue going on but we need a little more info. Where is the lacquer peeling off at? Is it between coats of lacquer or at the raw wood stain. Use a magnifying glass and look real carefully at a couple of spots where you peeled it off to make sure. You will be stripping off the bad stuff. (If you put anything on over something that is peeling off you are just asking for disaster) Either one coat or all the way down to bare wood. Bubinga isn't usually really oily but this batch could be and that is probably the reason for your problem. If it is then completely strip it down to bare wood, sand thoroughly, wipe down everything with acetone and then denatured alcohol (This will remove any surface oil) Do your staining and then seal with a 1 lb. cut coat of Zinnser Seal coat. This is a de-waxed shellac and it will adhere to almost anything. Scuff the shellac with 320 after drying and then apply your lacquer coats. I hope this helps...


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## buzzy (Aug 2, 2009)

I am sorry. Its wood dye. Its completely soluble in lacquer thinner. I applied 4 coats of lacquer and did not have this problem of blotchy patches. After I sanded with 360 and 600 grit sandpaper, I put another coat of lacquer. This is when i started getting blotches. Today I just sanded the damaged coat. Now it still has patches. The patches are dry like bare wood and very smooth.


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## Leo G (Oct 16, 2006)

It looks sort of like the lacquer has blushed, but that is not how it usually woudl look. How did you apply the veneer? Did the glue bleed through the pores of the wood?


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## Rick Mosher (Feb 26, 2009)

It is the finish lifting from the wood. You need to strip down completely and refinish as above instructions. The finish wouldn't have started lifting right away. Changes in temperature in your shop probably started the process, it don't take much when the finish isn't stuck to the wood.
You can probably take your fingernail to one of those white areas and scratch the finish right off to the stain.


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## buzzy (Aug 2, 2009)

The top and the right of cabinet shows sanding dust. Its the front that shows this flaw. I think it might be oil as i tried wiping it with water, even the water will not wet those areas.

The veneer is paperbacked and i used contact glue to stick it.


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## buzzy (Aug 2, 2009)

Now that I am sanding down to the bare wood, I would like to correct a few mistakes i made. The last time when i applied wood dye to the bubinga veneer the colour adhered unevely. 

1) How can i apply the wood dye evenly ? (The dye uses thinner as the solvent)

2) I would also like to fill the grains to get a smooth surface. When should i perform this step ? I am thinking of using timbermate grain filler (waterbased) http://www.timbermate.com/timbermate-wood-filler-is-the-only-non-shrinking-water-based-wood-filler-on-the-market Is there any problem in using waterbased filler ? 

What is the order I should perform these steps ? I would also like to lacquer.


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## ACP (Jan 24, 2009)

Could it be that you applied lacquer over a dye that's soluble with laquer thinner? If any of that thinner remained that would cause adhesion problems I would think. Lacquer thinner is used to clean up Lacquer right? One would think it would all evaporate off but maybe it didn't. Maybe a coat of shellac in between the dye and laquer would be a suitable barrier? Anyone else thinking on these lines or am I way off?


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## buzzy (Aug 2, 2009)

No the thinner is mixed with the lacquer to dilute it so it flows better. Anyways thank you ACP for your input. I am so desperate right now I am willing to try anything.


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## buzzy (Aug 2, 2009)

I have just sanded a small part of the problem area to the bare wood and wiped it with acetone on a rag. Then i applied lacquer to the area. The problem still persists.The lacquer in the non problem areas dry to a glass like shine but the problem areas are dull and rough. Now I am still looking for the zinnser seal coat. Would shellac do the same job as a zinnser coat ?


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## Rick Mosher (Feb 26, 2009)

I don't know what kind of shellac you have but it would be best to use de-waxed shellac if possible which is what the zinsser seal coat is. You can buy it online and I have heard of people picking it up at Home Depot.


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## Rick Mosher (Feb 26, 2009)

I have a couple of questions, When you wiped the surface down with acetone did the spots still show up? Is it possible that those are spots of glue on the surface?


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## buzzy (Aug 2, 2009)

When i wiped with acetone the spots did not show up. But the rag was a little sticky on those parts. Then the problem surface appeared to be clean. But when i put the lacquer over the area, it does not dry glossy like the normal areas, it dries to a rough surface. Now i am starting to think that the contact glue had seeped up to the surface. How do i get rid of it ?


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## Leo G (Oct 16, 2006)

MEK will dissolve contact cement. It may loosen the veneer though. Use a brush and wioe only the affected areas. Before you do this make sure it doesn't stain or bleach the wood.


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## cabinetman (Jul 5, 2007)

It seems so far the suggestions are hit and miss. This type of problem is prevalent in any finishing situation. That is, there is a problem, try to figure out what the cause is and then try to figure out how to solve the problem.

There is a possibility that the surface got contaminated before the dye, or after. From the looks of the spotting, it looks like something got spritzed. Another possibility is that the contamination came from your spray gun. It could be an oil buildup from excess moisture in the tank, airline, or the gun. Spitting from the gun can be a sporadic one time happening, or an on and off type of repetition. It could have been just a momentary spitting. The air at the gun should be cool, dry, and clean. 

You might drain the tank and introduce some water and a minimal liquid soap solution to wash out any of that greenish/grayish oily blob of gunk that builds up at the bottom. Rinse till clean. Install a bulb filter on the bottom of the gun. 

If you need help in analyzing your spray setup, say so. I can post a link on optimizing a system, which can help in troubleshooting.


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## scribbles (Mar 2, 2009)

i will take that link cabnet man


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## buzzy (Aug 2, 2009)

cabinetman said:


> It seems so far the suggestions are hit and miss. This type of problem is prevalent in any finishing situation. That is, there is a problem, try to figure out what the cause is and then try to figure out how to solve the problem.
> 
> There is a possibility that the surface got contaminated before the dye, or after. From the looks of the spotting, it looks like something got spritzed. Another possibility is that the contamination came from your spray gun. It could be an oil buildup from excess moisture in the tank, airline, or the gun. Spitting from the gun can be a sporadic one time happening, or an on and off type of repetition. It could have been just a momentary spitting. The air at the gun should be cool, dry, and clean.
> 
> ...


Thanks but i applied the lacquer with a brush.


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## cabinetman (Jul 5, 2007)

buzzy said:


> I am sorry. Its wood dye. Its completely soluble in lacquer thinner. I applied 4 coats of lacquer and did not have this problem of blotchy patches. After I sanded with 360 and 600 grit sandpaper, I put another coat of lacquer. This is when i started getting blotches. Today I just sanded the damaged coat. Now it still has patches. The patches are dry like bare wood and very smooth.



You didn't mention that you *brushed* the lacquer. All you said was you *applied* the lacquer. Whether it matters in this case..it may. Here you state you applied 4 coats and did not have a problem. That tells me it has nothing to do with anything previous which includes the dye, veneer, and glue.

I'm inclined to call it some kind of surface contamination. It could be anything, even a sneeze.


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## cabinetman (Jul 5, 2007)

scribbles said:


> i will take that link cabnet man



Here ya go:

http://www.woodworkingtalk.com/f8/problem-solving-11543/#post90194


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## buzzy (Aug 2, 2009)

cabinetman said:


> You didn't mention that you *brushed* the lacquer. All you said was you *applied* the lacquer. Whether it matters in this case..it may. Here you state you applied 4 coats and did not have a problem. That tells me it has nothing to do with anything previous which includes the dye, veneer, and glue.
> 
> I'm inclined to call it some kind of surface contamination. It could be anything, even a sneeze.


Sorry i forgot to mention that it was brushed on. I don't know what contaminated it. The problem came when i started to sand after i have let the 4 coats to dry. Could sanding too much cause such problems ?I used the dry sandpaper and another silicon carbide sandpaper. I have also cleaned the sanding dust with a wet rag.


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## cabinetman (Jul 5, 2007)

buzzy said:


> Sorry i forgot to mention that it was brushed on. I don't know what contaminated it. The problem came when i started to sand after i have let the 4 coats to dry. Could sanding too much cause such problems ?I used the dry sandpaper and another silicon carbide sandpaper. I have also cleaned the sanding dust with a wet rag.



Here we go again. What kind of rag? Wet with what?


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## woodnthings (Jan 24, 2009)

*It goes on and on...*

Just strip off the finish and start all over and take Rick's advice for sealing.
Problem will be using a chemical stripper may lift off the veneer.
This is truly a can of worms.
What you did or didn't do at this point is irrelevant. 
You need to start fresh. 
I feel bad for you and wish you well. Finishing is 90 parts science and 10 parts luck and skill. Unless you use a tried and true method or work with practice samples, the combinations of these different chemicals is not easily predictable.
Clean equipment, brushes, spray guns with moisture must not be a variable in the process, they should be absolute standards, otherwise there are too many unknowns in the equation.
:thumbsup: bill


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## buzzy (Aug 2, 2009)

Its a clean cotton rag wet with water.


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## scribbles (Mar 2, 2009)

There you go. Fresh lacquer will absorb water, and it is trapped between the layers. You cannot wet with water and apply over the top. I use a dry rag and compressed air to clean, or you can buy tack cloths. But you cannot use water.


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## scribbles (Mar 2, 2009)

Buff it with synthetic steel wool and lacquer thinner, you may be able to soften the finish enough to let the moisture out. Then sand it all with 220, and recoat. But you need to get enough heat in it to help it dry. I don’t think your finish is lost. Yet,


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## Leo G (Oct 16, 2006)

If it is water flood spray it with retarder and let it flash off, if water is in there it should release it. Hint, don't touch it - don't ask why I know that.


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## scribbles (Mar 2, 2009)

Leo got a link to retarder? That would be a lot easier than buffing it like I do. My method works but takes forever.


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## Leo G (Oct 16, 2006)

this is what I use


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## buzzy (Aug 2, 2009)

Scribble and Leo thank you so much. I shall try finding a retarder. What is a retarder by the way ?


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## buzzy (Aug 2, 2009)

buzzy said:


> Now that I am sanding down to the bare wood, I would like to correct a few mistakes i made. The last time when i applied wood dye to the bubinga veneer the colour adhered unevely.
> 
> 1) How can i apply the wood dye evenly ? (The dye uses thinner as the solvent)
> 
> ...


Sorry i ask again but hopefully someone answers this. Thanks


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## Leo G (Oct 16, 2006)

Retarder is usually a slightly hotter, slower drying thinner. Usually used to extend drying times in lacquer to prevent blushing. Blushing is what happens when water gets trapped in the lacquer film, usually caused by high humidity.


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