Lacquer problems

[Paul Sedory]

I'm finishing some furniture in my garage because I don't have an air conditioned spray booth or workshop. Since I'm in Austin and it's summer, it's hot and high humidity. I have tried using retarder and thinner and working first thing in morning but I can neither get it brushed on without brush marks or sprayed without orange peel. I have a turbine HVLP and even tried putting the hose in a bucket of ice water. Spraying seems to dry even faster than the brushing. I'm not sure what to try - more retarder or thinner or both, which method, another finish on top or something else? Starting to get frustrating.

[Wayne Lomman]

Use more thinner. With lacquer you can use as much as you want or need to. In hot conditions, 50% is not unusual. It means you can still work when it is 40C but no higher or it won't work at all. Do that first and modify the drying time further with a little retarder if necessary. It means extra coats need to be applied to get the required dry film thickness, but sometimes it has to be done.

Are you using the recommended thinner? It's best to use the one the tech data sheet nominates. It's th only way to get a degree of certainty about how it will perform.

Spraying will get the best results. Lacquer is not designed for brushing other than minor touch up. Cheers

[Paul Sedory]

Will try more thinner. Have a cheaper turbine HVLP with no adjustments so that may be part of the problem too. Would a varnish or shellac go on any differently in these conditions? I understand poly would not adhere well to lacquer.

[Jim Becker]

Paul, you do not want to spray an oil based finish...sticky-mess-city for sure. Shellac may exhibit some of the issue because it's also an evaporative finish like lacquer and may need to be handled in the same way as the lacquer.

[Wayne Lomman]

If you have no adjustments, then changing viscosity is your only control. Cheers

[Marc Jeske]

I spray basic old school non cat lacquer year round and often in E Tx.

I have a 25 yr old Graco HVLP "conversion" cup below gun.

Out in driveway.... some days it sprays better than others, but overall always works out for me.

I usually do not need retarder, if I do I add that % as per mfgr, not more like I do thinner.

Originally had lots of problems like you, and of course blushing.

Took time to learn, but I love it now.

Glad to help you over phone if you want to PM me.... text on web takes forever.

At least for most work pieces, now that I can spray I would NEVER go back to brush.

Sprayed lacquer typically dries to light finger touch in 5 minutes +- depending on thickness of coat.

Be aware - The maximum thinning % stated on the can has NO connection to use of the material, but totally due to environmental laws.

I myself, and many others, often thin up to 40% +.

Now, in a perfect world, like in a factory, they will thin less because their equipment will handle the viscosity.. and of course get more build thickness per coat.. but non optimized small setups usually need to thin a good amount to get sufficient atomization.

Orange peel is basically due to insufficient atomization, many possible causes of that... also, overly fast
drying gives less time for flowout.

Gun adjustment is very important.. and just as important is the order.. the sequence of adjustments.

If your gun is truly somehow not adjustable, you have no choice but to thin to the viscosity your gun needs... possibly also try increasing air pressure a bit.

I, personally, and many here will disagree, 99% of times stay away from other finishes now that
I have this down.

Marc

[Wayne Lomman]

Marc, I am with you on using solvent borne lacquers. Still the best furniture finish.

Paul, as Marc said, any half reasonable suction gun will help with your application technique. I still use a $40 Iwata knock off but it lays lacquer down perfectly. Cheers