concerns about humidity

Hi all, this is a great forum! I've learned alot from all of ya'll! I built a mission stile bed and now it is time for the finish. I stained it last week. The stain is dry and now I want to put on the finish. I want to spray shellac on it, but I will have to do it outside.(I don't have a spray booth) The high temps. are going to be in the low 90's all week with the humidity between 65% and 85%. What can I do to make sure I don't have a problem with blushing? Would brushing be better since I can do it inside the basement? I really prefer spraying, but if this is going to be a problem I'll brush.

TIA,
Lamar

I haven't done it with shellac but have with lacquer. That is spraying in a warm humid climate. I did have some blushing so am familiar with it in relation to the finish I was using. A couple things I did to help prevent it are these. Don't spray too thick. Warm the finish before spraying and you can get an additive for lacquer to slow the curing to reduce blushing. Sometimes I did all three just to make sure. In the end the finish came out looking very good. I think you will get a better finish spraying than brushing.

Thanks Bill, I'll try and spray some this weekend on a couple of test boards and see how it goes from there. I give your suggestions a try.

Thanks again,
Lamar

Wondering how your attemt at applying the shellac went?

Hi Bill, It went pretty good. I used a 1# cut for the first 2 coats. The first coat had some blushing, so I sprayed a light mist of alcohol on it and sanded a little and it came out fine. The second coat had a few small spots of blushing, and I just dampened a rag with alcohol and wiped away the finish in those spots and reapplied. Then I used a 1.5# cut for the 3rd and 4th coats. I ended up doing these 2 in my basement with fans to pull the fumes out. They came out better with no blushing. I'm very happy with the out come. Spraying is alot easier and faster than brushing!

Lamar

Lamar
Glad you are happy with the way it turned out.
Another comment on my experience though it was with lacquer not shellac, I found in two instances that blush appeared they disappeared before I got around to effecting my intended repair.
I think I would like to try some shellac. Might try to pick up some flakes to take back to PI with me.

Building a thick coat of shellac is an improper application of shellac.

The perfect shellac finish is the thinnest possible finish that is flawless. Too thick and shellac will alligator...

We get some nasty heat and humidity up here in Philly as well (although not as bad as GA) and the approach I have been using lately for spraying in conditions like that is ... don't do it. There are just too many variables to try and control and the environmental conditions are so close to the edge (and sometimes beyond) the manufacturers recomendations that it is just not worth it. If something does go wrong it is just too hard to pin down what happened.

If you have to make a deadline you have to do what you have to do but if you are just a hobby guy such as myself it is just easier to wait.

As a general statement - I really, really dislike the weather here in Philly between about May and September because of the humidity.