I have been using an airless rig for years when i spray laq. I was finally fed up with the clean-up and running laq through my hoses and it just became a problem. I had been eyeballing a binks cup sprayer and my wife finally got me one for my b-day. A 2001 binks. Well yesterday I was finishing up a tv cabinet and here are a few of the things I need to figure out. I know many people that swear by their cup sprayers so it must be me with the problems.
1. Keeping it wet. As i was spraying the back/inside, the air was “frosting” the area I just did. I suppose the rushing air was drying it too fast so I added more retarder. This seemed to work ok.
2. The area that the spray covered wet was limited to about 4 inches. I had to keep my gun about 6 inches away to get 4 inches of wetted area. Surely the gun is capable of moe than that.
3. It was humid out,…ok..real humid out….ok…it was about to rain. Do you add more thinner or retarder in these situation. (It had to be done yesterday)
4. It took ALL day. For one piece of furniture. Airless was 1/3 the time. Toward the end of the day the cup sprayer was having problems drawing the fluid out. I would have to release the cup and “jack” with the knobs to get it going again.
Any help with this would be appreciated. The gun was 253.00 I better learn how to use it right. The final finish was flawless. Turned out very well. Just took forever. thatnks for the help
Replies
Dear cutawooda,
Six inches from the target when spraying the inside of a cabinet back sounds a little low.
You ought to try to adjust the nozzle so that it has a small coverage and the pressure just so that spraying is done from a distance maybe up to 3 times as much as you mention.
In other words, inside spraying should not be from too close a distance due to rebound.
If having to spray close, the closer the much lesser pressure and HVLP guns are good at that.
Good luck.
Hi cutawooda,
I started out with a cup gun and switched to an airless . Part of the problems you had are because as you know air and some material are blown out of a cup gun. When I used the cup gun it seems as though I thinned about 50% but with the airless I thin 20% . Your mixture may need change ? Also the airless has greater ability to change the spray pressure .Cup guns are easier to spray small items or things like chairs or other intricate pieces. What I noticed was the cloud is no longer in the air all that material that's lost with the air . It seems the airless uses the material more efficiently with less in the air .It is very difficult to get a real wet coat on large flat surfaces with the cup especially when spraying up right without dry streaks in-between passes .Regardless of which rig you use for me the worst time to spray is about 55 degrees and raining. It may be different in your area .Also keep the siphon hole or tube clean and cleared on the top of the cup.
good luck dusty
"Toward the end of the day the cup sprayer was having problems drawing the fluid out."
It sounds like your vent hole was plugged up. I have an older Binks cup gun and regularly shoot pre-cat lacquer with no problems. A little retarder is required if it is very humid. Good luck, Art
Everywhere that I've worked for the last decade or so has had at least one 2001 cupgun. I personally don't like using them at all!!! It sounds to me like you've got a siphon-feed set up. Those are the worst IMO. What I hate about them the most is the amount of air flow you have to have to siphon the material out of the cup. Much, much better is a pressure-feed cup gun. I still don't like those much - vastly preferring to use a gravity gun. On stuff that's too big for using a gravity gun I switch to a pressure pot set up.
I think a lot of the frosting problem is caused by the excessive amount of air needed to siphon the material out. As someone pointed out... this can be negated by over reducing the material. But, then you're only putting half as much actual finish on.
What I would suggest would be to reduce lacquer about 25 - 30% with a mixture of MEK and PM Acetate. I typically start from a 50/50 blend baseline and adjust it to match the conditions. In hot or humid weather I use more PM Acetate (a retarder) than MEK. The retarder will help the lacquer flow out much better, while the MEK helps it flash off faster so as to mitigate the inevitable runs and sags problem that using a lot of retarder can cause. Plus, the MEK changes the surface tension of the lacquer in a positive manner. Basically the droplets of lacquer flatten out much better when they hit the surface. That coupled with the retarder can make a big difference in flow out.
Then I would reduce the airflow as much as you can while still maintaining a decent level of material flow and atomization. Using the MEK/PM Acetate mixture I have found that I can use air pressures that would yield orange peel with standard lacquer thinner but which don't when using this blend.
For what it's worth... I've been using the MEK/PM Acetate blend in nitro, precat and post cat lacquers and conversion varnishes for about 15 years now. There simply is no substitute IMHO. Flawless "off the gun" finishes are actually pretty easy to achieve with this blend.
"Rather fail with honor than succeed by fraud" - Sophocles.
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