>About to have my first try at spraying dope,what to use
>air brush or touch up spray gun? Looking to spray Sig
>Litecoat clear as a fuel proofer over colored tissue.
>What pressure to spray at? How much thinner and what sort of >working time do I have to clean up the spray equipment.
>A lot of questions I know, any help much appreciated.
The air brush will not have enough capacity unless you are just doing a small rubber powered plane. Normallyuse the touch up spray gun, and if you do a lot of painting on larger planes, you might even want a full size gun. The pressure is going to depend on the gun you use. Check the directions. What one person uses may work for his gun, but not for yours. You may get an idea, however.
SIG dope does not need as much thinning as Brodak dope does. SIG dope with SIG thinner will also be slower drying, both it its application and in the time between coats. It can take up to a week to cure before sanding, a month before rubbing out if you ever reach that point. However, for just fuel proofing tissue, sanding, and certainly rubbing out may not be an issue.
As for cleaning your gun, there really isn't a great rush, although doing it the sooner you can, is always best. But there is nothing wrong (usually) in leaving the dope in the paint gun between coats. Dope thinner will attack any residue left in the gun, even if the stuff hardens. You can soak it in thinner and always remove it later on. This also means that if you spary your coats on too thin or apply too much at a time that the thinner in the top coat will eat on down into the lower coats which can cause lifting and also slow down the curing process for the entire job.
Your SIG Lite Coat is already plasticised. A little more may help (a "little") but is usually not necessary.
Oh, and as mentioned, it is good to have a spray gun dedicated to the application of clear. There are always little specs of color that remain in some nook and cranny which will be dissolved the next time you add dope and thinner. So if you don't get the gun absolutely clean after using it to apply color, you may end up with a tinted clear the next time you attempt to use it for applying clear. Just remember, dope thinner will dissolve even dried and cured dope.
