Circles in sprayed shellac

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Forum topic by daviddoria posted 01-29-2014 09:45 PM 1173 views 0 times favorited 11 replies Add to Favorites Watch
View daviddoria's profile


66 posts in 1359 days

01-29-2014 09:45 PM

Topic tags/keywords: shellac hvlp

I am spraying (with an Earlex 5500) BullsEye SealCoat dyed with some TransTint. While several boards sprayed perfectly fine, on a few of them I got some sporadic circles/rings of color (see attached). Can anyone suggest what might be causing this?

Once we figure that out, I’m planning to just wipe it down with some denatured alchohol to try again – do you think that will remove the circles well?



11 replies so far

View CharlesNeil's profile


1602 posts in 3291 days

#1 posted 01-29-2014 10:16 PM

David, I know what the issue is ,if you can hold tight until tomorrow, I can help .. I was just shutting the “puter” down.. I have to run .

View pintodeluxe's profile


4825 posts in 2234 days

#2 posted 01-29-2014 10:26 PM

I am assuming you used liquid concentrated Transtint dye, is that correct?
If so, what concentration of dye did you use? For any tinting I do, I limit colorant added to 1 tbsp. per quart of universal colorant. However, the transtint dye is so concentrated, it would be a very small volume of dye per quart of shellac.

Could there be a contaminant in your gun from a prior project, or on the wood? On compressor driven systems a water trap is important to keep water out of the lines. Does your Earlex have a water trap built in? Many contaminants like wax and silicone can cause fisheyes.
Is this a refinish job, or new lumber?

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View daviddoria's profile


66 posts in 1359 days

#3 posted 01-29-2014 10:31 PM

pintodeluxe -

Yes, I used liquid TransTint. I used 0.5 oz (1 tbsp) of TransTint to 16oz SealCoat (This was the highest concentration recommended on the bottle) as I am looking to match a very dark brown.

This is a refinish job. I actually had stripped the piece (with chemical stripper and then sanded) and then sprayed it with dyed polyacrylic, but got terrible fish eye. The concensus was that there was some silicone left in the pores even after the stripping process, and that I should strip it again and this time use shellac as it shouldn’t have any problem with the silicone. I did so, and here we are :)

CharlesNeil -

Sure, tomorrow would be great – thanks!

View Finisherman's profile


227 posts in 1270 days

#4 posted 01-29-2014 11:19 PM

Initially, I thought that you might have a case of fisheyes, but that didn’t make sense, given that you’d sprayed on a layer of dewaxed shellac, a standard remedy for fisheyes. Rather, I suspect that the dye is bleeding out of the pores, after being reactivated by the alcohol in the shellac. I’d suggest keeping the new coats of shellac as light as possible so that you don’t reactivate the dye.

View daviddoria's profile


66 posts in 1359 days

#5 posted 01-29-2014 11:20 PM

Finisherman – To clarify – I did not spray a layer of just dewaxed shellac – I am getting this problem WHILE spraying dyed dewaxed shellac.

View JAAune's profile


1614 posts in 1737 days

#6 posted 01-29-2014 11:38 PM

I’ve seen this sort of issue appear in a few different situations.

First, if the finish is not atomizing properly, larger wet droplets can hit the surface. This usually results in a drop of colored shellac sitting on the surface and the dye tends to migrate towards the edges of the drops while leaving the middle lighter in color.

Second, spraying a full wet coat of toner can result in uneven coverage. Wherever the shellac coat is heavier it will dry slower and with uneven coloring. The darker the toner, the more pronounced this effect becomes.

Another possibility is that finish is slowly building up on the nozzle of the spraygun and at intervals, it gets spit onto the surface of the wood and disturbs the layer of color. Once you spray toner on the wood, you can’t let any shellac or alcohol hit the surface otherwise the coating gets dissolved and ruined. Keep an eye on the nozzle of the gun to make sure you aren’t getting excessive buildup of finish there.

The easiest way to use toner is to spray it in several passes using a very fine mist. The shellac should dry almost as soon as it hits the surface so it won’t run at all. This completely avoids the risk of drips or runs and makes it easy to see where more toner is needed. Once the color looks good spray on a light coat of some sort of finish that does not use alcohol as the primary solvent. This will lock the color in and permit normal spraying afterwards without risk of damaging the colored layers.

I have seen shellac affected by fisheye before if it is sprayed on too heavily. Light coats work best. Once the contamination is sealed you should be able to go back to spraying normal coats.

-- See my work at and

View CharlesNeil's profile


1602 posts in 3291 days

#7 posted 01-30-2014 02:59 PM

The issue here is either contamination or surface tension.. or a combination.

Finishes do not like to turn corners .. meaning, if you look there are some small holes, and the finish repelled back from them. I suspect there could also be some contamination , but the finish is pushing back and not wanting to “turn ” into the hole . If you have ever sprayed a semi porous wood like walnut or mahogany , odds are you have seen a similar situation, where the finish can try to sit on top of the area around a deeper grain.. Mahogany can be horrible .

You can also have a situation where the finish soaks in and the pore expands and pushes the finish back out, just like on oak if you oil it too heavily,,, the oil can push back and leave droplets .

In this case because it has a toner in it, you see it more prevalant . I would simply wipe it with some denatured alcohol , to redissolve the shellac and try to work it into the holes, then clean it with some naphtha, and lightly dust another coat on. This typically occurs when you spray a wet coat, If you can dust several light coats on its usually isn’t too bad.. The other thing I like to do is to wipe a coat of shellac on,first , this allows the mechanical push needed to force the finish into the grain. It also seems that the smaller the hole or grain, the worse it can be.

View Earlextech's profile


1157 posts in 2111 days

#8 posted 01-30-2014 03:27 PM

I just want to chime in to ‘pintodeluxe’ to explain that HVLP does not need a water trap as all HVLP’s use warm dry air. The exact opposite of an air compressor. This is one reason why you should finish with HVLP.

-- Sam Hamory - The project is never finished until its "Finished"!

View daviddoria's profile


66 posts in 1359 days

#9 posted 01-31-2014 02:09 AM

Thanks, all, for the excellent information and suggestions. I wiped it down with denatured alcohol and the circles came off very easily. I sprayed a few very light coats and they did not return. I would guess that I was just too long on the trigger in those few spots and that it was the “dropplets formed” problem, that then dried into circles.

It seems like with this light of a coat I might need 6-8 or so coats to get the color I’m looking for – does that sound reasonable? (it sounds like an awful lot to me!). If I do need to do that many, can I wait only a short time, say an hour or so, between coats?


View JAAune's profile


1614 posts in 1737 days

#10 posted 01-31-2014 02:35 AM

With shellac I typically recoat as soon as the previous layer is dry to the touch. If you’re “dusting” the finish like Charles Neil suggested the shellac will usually be dry enough to recoat within minutes. On larger projects I’ll usually start on one end and by the time I finish spraying I can just go back to the beginning and continue working.

Thinning the shellac with a little alcohol may help some. It’ll keep the colored shellac from getting too thick from all the coats you’re spraying yet deposit the same amount of coloring.

You’ll want to avoid sanding between coats during the coloring phase to prevent burn-through.

After the first layer of clear coat goes on you’ll be able to scuff sand to smooth off dust nibs. The second layer of clear coat should be nice and smooth if everything was done properly.

-- See my work at and

View hydro's profile


208 posts in 1172 days

#11 posted 02-01-2014 12:22 AM

Those circles are fisheyes, almost assuredly caused by residual silicone in the pores of the wood. Look at the centers of the circles, see the pores? Your mention that this is a “Refinish” gives the clue to the source of the problem- Furniture polish containing silicone.

Using shellac will not cure this by itself. Your “dusting coat” idea just laid down a coat of finish so thin that it dried before it could retreat from the silicone. Another thick coat will probably fisheye all over again.

The only cure for this issue on refinished projects is to use “Fisheye killer” in the finishing material used to coat the project. No amount of washing, scrubbing, rinsing etc, will remove the silicone.

-- Minnesota Woodworkers Guild, Past President, Lifetime member.

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