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I have just purchased a new Iwata gravity feed spray gun (AZ3 HTE 2) for spraying Mirotone pre-catalysed lacquer. I'm planning on applying 3 coats/day with about 1 hour between coats. Can I leave the lacquer in the gun between coats? Do I need to remove or clean any parts of the gun, or can I just hang the gun from a hook while I wait?
Cheers
Bit dependent upon the day's temperature and the viscosity of the lacquer.
If it's not too hot (say over 27 degrees) and you're using the precat thinned a minimum of 10:1, just pull back on the gun's trigger about half way to allow compressed air to run through the needle and air cap, blowing out any lacquer sitting about.
But check the air cap and needle first - if you're spraying a large area and there is a buildup of lacquer at all visible, take the air cap off, and sit it in gunwash or thinners between coats. However, I'd probably empty the gun completely, and run a quarter of a cup of gunwash or thinners through the gun before taking the air cap off to soak it between each coat.
Presumably you've also got a smallish needle / aircap setup for the gun for lacquer? You need to be zealous about straining anything you put through the gun - paint strainers, not stocking or coffee filters - the thinners in the lacquer will make short work of such alternatives, adding to rather than filtering your lacquer. Pick them up at spraypaint / auto suppliers - use the Fine grade. Pylon & BC Coatings also sell them.
Thanks for the response.
My gun has a 1.8mm tip. Mirotone recommend a 1.5-2.0mm tip for the 3220, so I just split the difference.
I'll be thinning the lacquer at 40% for initial coats and 30% for top coats (Mirotone rep's recommendations). I've got the slow thinner (Mirosol 1242)
I'll buy myself some gun cleaner. I hope it's cheaper than the $40 per 4L I paid for the Mirosol. :oo: I think I'll play it safe and just run a bit of cleaner thru the gun between coats.
If you're using gunwash (which will certainly be cheaper than the 4lt price for Mirosol - if you're going to be doing a bit of spraying - price their 20 litre drums for the standard Mirosol, and buy the slowest of their thinners in 4 ltr tins, mixing and blending the two to suit the conditions when spraying). Sorry - if you're using gunwash or Mirosol to rinse the gun between coats, make sure you have sprayed through the gun a blast of the topcoat before you lay any down on the surface.
The only time you ever want to put straight thinners onto a sprayed surface is when you've got a lot of blooming - a misting of thinners and some warm air may remove the bloom. Note the word may.
Just on pricing issues - if you're a COD over the counter customer, you'll pay a premium. If you're going to be using more than 4 litres of lacquer a month, see if you can set up a trade account either with your manufacturer of choice or one of the many industrial supply resellers around. And make sure any rep knows you're shopping around - they'll usually try to match other offers.
Thanks again. I'll be lucky to get thru a 4L tin in a year so I don't mind doing over-the-counter.
I'll certainly make sure I blow the thinner out before I point the gun at the guitar.
Cheers