for those who still use butyrate dope
#26
Lacquer is not fuel proof, just as Nitrate Dope is not fuel proof. An excellent thinner for Dope is Automotive "Reducer" . It is slower than lacquer thinner, acetone or MEK. And it's a lot cheaper than Dope thinner.
#27
And by the way, you may wonder why in the world you would want your "thinner" to be "slow"...
Well, you do, and the reason is what we called blushing. When "paint" is sprayed the sprayed material is "atomized" into a fine mist, which gives it a huge amount of surface area -- a huge amount of evaporative area. Because of that, there's a lot of evaporation going on in the spray and evaporation consumes energy, so it cools the spray. That cooled spray material is often cooler than the dew point of the air it's going through, so moisture (water vapor) in the air condenses onto/into it. Then, if the "paint" dries quickly on the surface being finished, that water is trapped in the polymer film that the "paint" is transforming into, making the finish look cloudy, milky, or even whitish. When painting a car (especially if it was a cooler and/or wetter day) we'd use an additive called a retarder to slow the polymerization process so the moisture could evaporate back out of the finish material, so it wouldn't be trapped and cause the new finish to blush.
Just an FYI.
(Of course there's also the desire for each pass of the spray application to meld with a still "wet" adjacent pass so there aren't visible separations between them, but I don't think that's nearly as big an issue -- and it's really not an issue at all with lacquers because of the particular way they harden.)
Well, you do, and the reason is what we called blushing. When "paint" is sprayed the sprayed material is "atomized" into a fine mist, which gives it a huge amount of surface area -- a huge amount of evaporative area. Because of that, there's a lot of evaporation going on in the spray and evaporation consumes energy, so it cools the spray. That cooled spray material is often cooler than the dew point of the air it's going through, so moisture (water vapor) in the air condenses onto/into it. Then, if the "paint" dries quickly on the surface being finished, that water is trapped in the polymer film that the "paint" is transforming into, making the finish look cloudy, milky, or even whitish. When painting a car (especially if it was a cooler and/or wetter day) we'd use an additive called a retarder to slow the polymerization process so the moisture could evaporate back out of the finish material, so it wouldn't be trapped and cause the new finish to blush.
Just an FYI.
(Of course there's also the desire for each pass of the spray application to meld with a still "wet" adjacent pass so there aren't visible separations between them, but I don't think that's nearly as big an issue -- and it's really not an issue at all with lacquers because of the particular way they harden.)
#28
Moderator
"Is lacquer fuel proof" is just about the same as asking "Is paint resistant to UV" or "is enamel abrasion resistant." Which lacquer are you asking about? By definition, lacquer is just a type of paint that can be rewetted by the same solvent it was originally thinned with. There are dozens of different formulations of lacquer, each one designed for certain properties. For example, nitrate dope and butyrate dope are both lacquers. Nitrate is very sticky and can serve as a base for paint since nearly anything will stick to it. So it's great for adhering fabric covering to a plane or sealing wood that you want to paint. But it's not fuel proof. Butyrate will gloss up nicely, will tighten the covering as it dries, and is durable and fuel proof. But nothing other than more butyrate will stick to it. Both are lacquers, but have very different properties.
#29
There are two companies making dope products; one is Certified Coatings and the other is Consolidated Aircraft Coatings Consolidated Aircraft Coatings | Home (Randolph, Polyfibre, Ceconite, Stargloss).
Brodak is Randolph and Sig "may" be Certified Coatings (Aircraft Spruce house brand) but I haven't done the litmus (smell) test.
Polyfibre is not dope but a vinyl finishing system. Consolidated Aircraft Coatings | Our Products. The same for Stargloss. Consolidated Aircraft Coatings | Our Products
Mixing the different products = disaster. None of these products work together. I use lacquer thinner from HD Aviation (or Lowes) to clean equipment and nothing else.
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Brodak is Randolph and Sig "may" be Certified Coatings (Aircraft Spruce house brand) but I haven't done the litmus (smell) test.
Polyfibre is not dope but a vinyl finishing system. Consolidated Aircraft Coatings | Our Products. The same for Stargloss. Consolidated Aircraft Coatings | Our Products
Mixing the different products = disaster. None of these products work together. I use lacquer thinner from HD Aviation (or Lowes) to clean equipment and nothing else.
Search Results from Aircraft Spruce
Search Results On Wicks Aircraft Supply