Digger-RCU

Greetings all.

I know this question has been asked before, but I must revisit it.

I have been painting my models with Model masters Acryl paints, and I need a clearcoat that will actually work.

I have not found a waterbased clearcoat that is really fuel proof in the heat and humidity of Corpus Christi. (actually using a waterbased urathane was just about the worst thing i have done to one of my planes)

Lacquer based clear coats are not fuel proof. ( I have tested)

Oil based urathanes yellow when they are applied. (Although they seem to be fuel proof)

I am using 25% nitro fuel.

I have thought about automotive clearcoat. Will this work fairly well? (it will be really glossy I imagine)

Please someone tell me what the magical product is that will fuelproof my plane, and look good?


Thanks a bunch ahead of time!

Randy (Digger) Birt

dennis

My Feedback: (90)

Unless you have the skill and the place and protective apparatus available for automotive clearcoats, I'd stay away from them. Yes they are very glossy but extremely TOXIC to work with. You can ruin your health in a heartbeat working around this stuff without a full mask and complete outerwear protection. It will also absorb through the skin thus the protective clothing being needed.
You can use a product that I've had very good luck with called PERFECT PAINT. Used to be made by Chevron paints and carried by Tower and Brodak. Another is Nelson clear with crosslinker, another is Stitts but that has to be used as part of a complete paint system as it is a vinyl paint process.
You should be aware that no clear will ever stay completely clear with the exception of epoxy clears. They all turn eventually even dope finishes will yellow and crack eventually. But with the proper clear usually your model is history before that happens.

A final product is Glass Kote which is a 2 part epoxy paint that is also compatable with K&B and Hobby Poxy paints. Do a Google search for their website.
Dennis

skaliwag

My Feedback: (1)

Flying Models had a great article about this a couple of months ago. May 2004 I think. The C/L stunt people use it.
Dennis is right about the toxicity of this stuff. In fact when I talked to one paint store he was not even interested in selling it to me untill I showed him the magazine and he accepted that I realized how dangerous the stuff was. You need a Deevo suit to play with this one.

Andrew

Digger --

I have to vote for butyrate clear dope -- same stuff Tower and Brodak have for sale. You can also get it from SIG, Aircraft Spruce and Speciality, and WICKS Aircraft. I tend to buy both Nitrate and Butyrate clear from the aircraft supply houses; also microballoons due to the lower pricing in quantity. You will need SIG Litecoat or Butyrate non-tautening. These have a plastisizer added to reduce shrinkage - without it, lightly built planes will curl up. Nitrate is not fuelproof, although it has slightly better adhesion qualities for sticking tissue, silk or silkspan to balsa. It also tends to shrink a little more.

Most clears will brush on, but need to be thinned with 1/3 thinner. They can also be sprayed with a touchup gun or airbrush when thinned 50/50. Common lacquer thinner will work, but may cause the pigment in some colored dopes to clump -- it is not a problem with clear. Butyrate will hold up well to raw fuel when cured, but needs to set a few days. It dries to the touch in no time, particularly when thinned. It will eventually yellow slightly, but only after 15 to 20 years.

When we didn't have all the new fangled stuff, we used to add a couple of drops of castor oil to the dope to act as a plastisizer - slowed drying, reduced blushing caused by high humidity and lowered the shrinkage. Many folks don't care for the odor; however, to me, it smells like fun.

the "other" Andrew

Digger-RCU

Andrew, Thanks for the reply,
I have some butrate. I thinned it, and sprayed it through my airbrush. It made the acrylic paint crack and peel up aff the model. Sort of diasterous. Is there a way to get the clear butrate to work over the acrylic paints?

Thanks a bunch.

Steve and Dennis, thanks for the reply. I am sure i wont try to shoot the automotive paints myself, but the idea has come to me that i might go to my friendly auto body shop, and ask them how much they might charge to shoot the plane!!!! (Grin)


Randy (Digger) Birt

Andrew

Randy --

I'm guessing that you sprayed a "wet" coat. The dope alone is carried by a solvent (thinner) and adding thinner for spraying makes it more potent -- even using a dusting technique of several light coats, you might still get lifting. First, make up a couple of test panels -- all your planes look too nice to experiment on.

Nitrate is compatible over acrylic lacquer and acrylic enamel, but not over butyrate. Spray several light barrier coats of nitrate (which is NOT fuelproof), then final coat with butyrate. Here is a [link=http://www.scaleaero.com/chemcompat.htm]compatibility chart [/link] listing which paints may be used over or under others. Nitrate is much more forgiving, but cannot be your topcoat with 1/2A fuels.

Andrew

Ragwing

My Feedback: (2)

Digger,

I asked the same question a while back in the Q&A forum, all the guys there told me to use an automotive clear coat. For $25 I got enough two part to last me a loooonnngg time. I haven't had any problems at all with the finish and 25%, but I haven't been flying for very long either-so far so good. And the finish is beautiful, smooth and so glossy. As far as health affects, I probably die in a few years of some bizarre ailment. I've just been spraying it outside and wearing a respirator. Well no, I take it back, I did spray it indoors this winter without a respirator--yeah I'm a gonner. But the finish looks really good.


Derek

ZAGNUT

My Feedback: (1)

tyvek or leather?

dennis

My Feedback: (90)

Guys ,I'm not kidding about the toxidity of automotive clearcoat, the modern stuff is extremely toxic.If your spraying anything you should always have a decent resperator.
Years ago in the 60's when Epoxy paint came out we sprayed without a mask. That stuff is cumulative in it's effects. Any that got in your lungs stayed and eventually you reached a toxic level. Had a friend die of respatory failure from the stuff. This newer clearcoat stuff is so toxic that auto makers have it put on completely by robotic machinery. custom painters use self contained air packs and chemical suits. You can joke about it but believe me it is a killer.
Dennis

flyinrog

My Feedback: (1)

Digger, most paint now a days is 2 part , that is base coat/clear coat///as long as you masked off the parts you dont want sprayed,(probably need to remove anything you dont want sprayed as there is significant overspray) your friendly local painter may do it for nothing if he has something lined up to spray anyway cant hurt to ask..
Dennis is right, some of these products are extremely dangerous...Rog

BMatthews

Imron is one brand name for a two part polyurethane clear. There are other similar ones. I'd just like to echo Dennis' warnings. This is not stuff to be trifled with. The effects in the end are severe nerve damage that has a very Parkinson's like effect and it does not take much exposure to seriously affect your body. Not MY idea of a good way to end my days.

It won't be cheap in model terms but if you want to put this stuff on your model I like the idea of a body shop doing it for you. Just one coat should do the trick.

uliner

My Feedback: (2)

this will work
http://www.klasskote.com/

it is an epoxy based paint a lot like the old KB superpoxy.

also Nelson hobby has a water based epoxy clear, that with the crosslinker should be fuel proof with high nitro.

I have had good luck with 2 part clear epoxy finishes used for woodworking.

The auto paints are bad, but your exposure is very short.
Aircraft Dopes are less toxic, but you need a long exposure to them to get a good finish, many coats, lots of thinner and sanding.

some would argue that with proper care the low exposure to the auto paints is "less unhealthy" than spraying 15 cotes of dope without a mask.

For small airplanes all the messing around with autopaints may not be worth it, spray booths and and the resperators etc.

I still have a little superpoxy clear that I am using up. then I will try the klass kote stuff.

make friends with your local body shop and see if they will shoot it with clear when they are shooting clearcoat on a car, that way it shouldn't cost too much. There may be enough left in the gun to to the work.

uliner

Sport_Pilot

Acrylic lacquer is fuel proof to about 20% nitro. Nitro based lacquer is not fuel proof at all. Most cans marked lacquer at the hardware store and many at an automotive parts store will be nitro or nitrate based. If it doesn't say it is acrylic lacquer than it is nitrate. This is the favorite paint of the C/L stunters who get judged on apperance. Since they repaint every year they don't need the more durable polyurethanes and epoxies.

DesignMan

I have flown with a bunch of Nats Level CL flyers, and never met one that refinishes his models more than once a decade, if that. It is an unbelievable pain to strip and refinish, and most just build a new plane a year.

I have found that you can get a small quantity (about 8 oz) of good clear 2-part epoxy from craft stores. The use it to cover decoupage placques. It can be thinned with denatured alcohol or lacquer thinner. Very FuelProof!

Andrew

I've located a [link=http://www.modelflight.com/weight.html]chart of comparative weights[/link] for different coverings and finishes, but have found nothing on the weights of automotive clearcoat or two part clearcoats. Have any of you run across some more recent tests?

ebeneezer3

MinWax polycrillic is said to be fuel proof. Its water based and easy to use. I hope its fuel proof and doesn't yellow, I'm just finishing a plane covered with silkspan put on with that pc stuff. I painted with artist's acrillics, not good shows brush marks but is fuel proof, then a top coat of straight polycrillic. There have been threads about this stuff so thought it was worth a try. I guess I'll find out. Ted

Digger-RCU

After much research and advise, (Thank-you all) I have come to the conclusion that at least a couple of decent clear-cotes actually exist.


I Looked up Nelson's, and was very impressed with the information concerning his product.
(two-part, water-based epoxy paint. with over 100 colors) I called him, and he offered to send me a sample to try. If his product is as good as he says, I wont be using anything else.

I certainly would not want to work with anything that is as toxic as what y'all have discussed here, but letting an auto body shop shoot a plane does sound interesting.

Ebeneezer3, please save yourself the heart-ache, and dont put that lousy polycrilic on your plane. It will not be fuel-proof!!!!!!!! It wil turn into a sticky mess that will attract every dirt molecule in the area. Use the above the advise by the guys here. look-up Nelson or perfect paint. You will be glad you did.


Thanks again guys, I will give y'all a report when I get the Nelson paint.

Randy (Digger) Birt

skaliwag

My Feedback: (1)

I think Towre has Perfect paint on sale this week.
http://www.towerhobbies.com/listings/listinva.html

Andrew

It looks like Perfect has changed their formulation to polyurethane and away from butyrate. This is apparently fuelproof up to 15% according to the attached tech notes.

the "other" Andrew

dennis

My Feedback: (90)

Perfect Paint was never Butyrate to the best of my knowledge. It was an alklid enamel and iIjust used it last month and it still seems to be an enamel. Dennis

Andrew

Hi Dennis --

Several sites I have run across lately have referred to Perfect Paint as polyurethane based or just polyurethane. I don't know if alkaloid enamel and polyurethane would be considered the same -- I didn't think they were. Both Tower Hobbies and Hobbylinc.com list Cheveron Perfect Paint as polyurethane -- which is not to say that it may be a misprint.

However, there is nothing on the Cheveron site to indicate what the basic compositon currently is. I've emailed Cheveron for a clarification -- if they respond, I'll post the answer.

Either way, it seems to be well liked and has a host of gloss and camo colors to choose from.

the "other" Andrew

ebeneezer3

Sadly, Digger is right, I've completed the model, see below, and raw Sig fuel with 25% nitro attacks it. The thread I saw must have referred to Gasoline. Oh well maybe it's only the nitromethane that attacks this finish and not the castor.

The plane is a Fred Reece design from RCM plans, Haf-a-dussen is the name. Like Digger, I'd like a good clear coat.

mclintock

My Feedback: (3)

Does nitromethane eat through car wax?