Anyone spray polyurethane?

I often use it.  It is cheaper than gloss lacquer.  I use it from both spray cans and brush cans.  I both brush it and airbrush it.  I often use it on wood bases.  I have used it on scratchbuilt wood models.  It is not as brittle as lacquer.  I have had gloss lacquer crack with weather changes on large wood models.  When brushing or airbrushing, I thin it with the same thinner I use for enamels.

I have found a spray can- forget the brand- that claims it is twice as thick and glossy as regular gloss urethane, and used it on a couple of bases.  Seems to work fine with fewer coats.

I used to spray it years ago through regular siphon feed 1/1 spray guns for finishing furniture. I thinned it with Dupont 3812 synthetic enamel reducer. So the answer to your question is yes.

You don't mention whether or not you use it on plastic models. Has anyone done this? What were the results?

JMorgan

You don't mention whether or not you use it on plastic models. Has anyone done this? What were the results?

 

I have not used it on plastic models fwiw..

JMorgan

You don't mention whether or not you use it on plastic models. Has anyone done this? What were the results?

 

Yes, I have used it on plastic models, but as a clearcoat, so the model is already primed and painted.

Not sure what you are referring too.  I take it to mean catalyzed urethane like we use for automotive finishing.  If so, yes I have and it works great.  But it is an extreme health hazard so you need to be careful how you work with it.  You don't spray that stuff indoors ... I don't care what kind of spray booth you have.  And you always wear a respirator mask and gloves.

Paul

Hmmm, I took him to mean hardware store poly like Minwax and such. Again I've shot that but on wood. I've also shot Polycryl. His original question was if anyone sprayed it, to that I say yes. Later the question became plastic models, to that I answer no. And like Don, if I did spray it on models it would undoubtedly be over primed paint, not directly to plastic, and as clear coat...

You couldn't pay me to spray catalized poly clears or paints. I left 1/1 painting when they became the norm in industrial fleet trucks. A spray mask and gloves is not sufficient, we went in booths with suits on and pressurized helmets, that stuff can even enter through skin and especially eyes. Modelers have 0 need to be subjected to the dangers of such materials. I know many do it but I absolutely will not touch it. There are plenty of other good options out there today. The human body can rid itself of many toxins but that catalized stuff goes in and chemically cures, the body can't process it out. I've been to classes, read the documentation and heeded the warnings by getting out of painting that stuff. There is a limit to how much a nice finish is worth.

I had a little race car, a 3/4 midget.  The body panels all came off and were small enough to get into the basement.  I wanted a metallic red for it, and the color was only available in acrylic enamel, a catalyzed paint.  I bought it, and in spite of the warning, I tried to spray it with a dust mask.  After a few minutes I almost passed out from the fumes.  I wasn't even able to clean out the spray gun!  After that I bought one of the fancy masks to finish the paint job, but I have never since used a catalyzed paint. 

Certainly too much complexity to use on a model when I can get all sorts of paints that do not require such measures.  I do have a spray booth, and have been building models for about seventy years, so the model paints I use seem to be not that harmful.