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General control line discussion => Open Forum => Topic started by: Mike Griffin on October 03, 2011, 07:37:16 AM
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Just got off the phone with one of my suppliers for Dope and thinner. It is now $90.00 for a gallon of Nitrate Dope and a gallon of Nitrate Thinner. Got to be a better way
Mike
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Another reason to go electric. LL~ LL~
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Another reason to go electric. LL~ LL~
GOOD POINT DOC
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Yea, I just looked up stuff on Aircraft Spruce. Randolph's is a bit less than Certified (a dollar or two). Thinner going for about 37 a gallon. Not cheap, but it is what it is.
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Also, remember that thinner is likely to be available locally. I use PPG Acrylic lacquer thinner from a store dealing in automotive paint. This works nicely with Briodak dope products. A gallon is, I think, about $35.
Floyd
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I use Dupont thinner for everything and its around 35 a gallon.
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I just went to Aircraft Spruces site. I also have bought from them for a while also.
I am seeing $44.10 for a gallon of Nitrate high solids dope and $45.71 for a gallon of Nitrate thinner. That is about 15-20% higher than the last time I bought it.
Mike
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Remember, fuel prices are thru the roof and they have to make a profit also.
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Another reason to go electric. LL~ LL~
Why's that?
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Well I guess I am going to have to get better at applying the monokote type coverings.
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I have been using Dupont 3608s thinner for years in both nitrate and butyrate. I bought the last gallon a couple of years ago for less than $20.00. I am running low, so will see what it costs now.
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Have you tried Sig?
One of the reasons it is high is the HAZMAT shipping. You could possibly buy it from SIG in smaller quantities to equal what you need and not have to pay the hazmat and it would be less....just thinking out loud here.
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Why's that?
Because you don't need fuel proofing, everyday Krylon works just fine and at my local hardware store it's only 5 bucks a can.
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(Howard is going to point out that nitrate dope is not fuel proof by any means.. which sorta nulls out the "go electric" argument)
I prefer nitrate for attaching silkspan, and use old-fashioned talc mixed in it to make a filler coat. It's stickier and lighter in weight than butyrate, and you can spray butyrate (or most anything else) over it, but not vice versa. It is less tautening (grammar?) than butyrate I believe. Some people use it only on fillets to get better butyrate adhesion and prevent blisters.
IF you spray a wet enough (or "retarder" laden) coat of butyrate over "dry" nitrate, the thinner can dissolve it and you'll get a chemical fight, staged at the molecular level, between nitrate and butyrate. Many people fear that result and avoid nitrate. Also there is the rumor that the slightest scratch in a butyrate top coat can expose the non-fuel-proof nitrate substrate and fuel mist will then destroy your model.
I acknowledge such things can happen and my best advice is "just don't do that"..
Actually, I'd love to find a nice water based non toxic paint with similar gluey, filling, and lightweight properties to replace nitrate dope for use over silkspan. (edit.. I forgot about corn starch)
L.
"Endurance is patience concentrated." -Thomas Carlyle
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Also there is the rumor that the slightest scratch in a butyrate top coat can expose the non-fuel-proof nitrate substrate and fuel mist will then destroy your model.
I acknowledge such things can happen and my best advice is "just don't do that"..
That's pretty much what has happened to my current airplane. It got wet waiting for flying to be suspended, then the pipe heat steamed the joints in the pip tunnel open. Then oil got under the paint, separated the nitrate from the paint and balsa, and then bubbled up.
Brett
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I have been using Dupont 3608s thinner for years in both nitrate and butyrate. I bought the last gallon a couple of years ago for less than $20.00. I am running low, so will see what it costs now.
Jim,
DuPont has discontinued manufacturing lacquer based products along with the 3608 thinner. If you can get any, it will be old stock so buy as much as the supplier has.
Orv.
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Don't forget about Wicks Aircraft either. I've gotten good service from them in the past. A gallon of Randolph non-taughtening clear from them is $44.27, a gallon of Butyrate thinner is $28.31. Nitrate prices are similar.
http://www.wicksaircraft.com/catalog/product_cat.php/subid=8644/index.html
Gary
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Yea, I just looked up stuff on Aircraft Spruce. Randolph's is a bit less than Certified (a dollar or two). Thinner going for about 37 a gallon. Not cheap, but it is what it is.
I am sitting here looking at an invoice from Aircraft Spruce for a gallon of Randolph butyrate thinner that I picked up last week showing a price of $25.40 for the gallon.
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(Howard is going to point out that nitrate dope is not fuel proof by any means.. which sorta nulls out the "go electric" argument)
I prefer nitrate for attaching silkspan, and use old-fashioned talc mixed in it to make a filler coat. It's stickier and lighter in weight than butyrate, and you can spray butyrate (or most anything else) over it, but not vice versa. It is less tautening (grammar?) than butyrate I believe. Some people use it only on fillets to get better butyrate adhesion and prevent blisters.
IF you spray a wet enough (or "retarder" laden) coat of butyrate over "dry" nitrate, the thinner can dissolve it and you'll get a chemical fight, staged at the molecular level, between nitrate and butyrate. Many people fear that result and avoid nitrate. Also there is the rumor that the slightest scratch in a butyrate top coat can expose the non-fuel-proof nitrate substrate and fuel mist will then destroy your model.
I acknowledge such things can happen and my best advice is "just don't do that"..
Actually, I'd love to find a nice water based non toxic paint with similar gluey, filling, and lightweight properties to replace nitrate dope for use over silkspan. (edit.. I forgot about corn starch)
L.
"Endurance is patience concentrated." -Thomas Carlyle
Hi Larry, nitrate actually tautens more than butyrate but the dried nitrate film has a lower tensile strength than butyrate.
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Because you don't need fuel proofing, everyday Krylon works just fine and at my local hardware store it's only 5 bucks a can.
I have yet to see a 20 point finish with Krylon paint.
Larry, Buttafucco Stunt Team
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I posted a list of part numbers and prices from Aircraft Spruce Specialties, for Randolph and Certified dopes and thinners, on the Stuka Stunt Message Board this morning.
There is also some info on other thinners, on the very same thread
Larry, Buttafucco Stunt Team
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Actually, I'd love to find a nice water based non toxic paint with similar gluey, filling, and lightweight properties to replace nitrate dope for use over silkspan. (edit.. I forgot about corn starch)
Nelson's point certainly fits the bill up to the "gluey filling and lightweight" part -- and I'm not sure it doesn't do for lightweight.
I have painted Polyspan with it, but that was for a very casual model that was just stripes on Polyspan.
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Of course, in liquid form it's about 4x more expensive than dope -- but if it covers more than 4x as well, I guess you'd get it back both in weight and cost.
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I have yet to see a 20 point finish with Krylon paint.
Larry, Buttafucco Stunt Team
You aren't shaking the can long enough, Larry. For front-row quality, you need to shake it vigorously for three minutes. This is difficult for a man your age, but it pays off in the finish. Hope this helps.
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You aren't shaking the can long enough, Larry. For front-row quality, you need to shake it vigorously for three minutes. This is difficult for a man your age, but it pays off in the finish. Hope this helps.
Ouch, that hurt.
Larry, Buttafucco Stunt Team
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Why's that?
Don't have to fuel proof every thing. Of course I never thought about the battery leaking. VD~
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Electric models are fraught with their own problems. Due to the presence of a strong rotating magnetic field in the engine bay, you need to use a non-ferrous paint. Otherwise it will get magnetized and create a major drag on the motor.. (Avoid iron spinners for the same reason.)
And the coming cryo-fielded motors running off the butane fuel cells will be even worse; even non-ferrous materials will be affected by the ten fold increase in the rotating magnetic field strength.. And liquid nitrogen escaping from its dewar will easily damage the finish. The really exotic setups using helium will be worse, due to the small size of the He molecule and its ability to escape containment. Finally, hydrogen will complicate the problems further.
http://www.ficklegrubberinstitute.com/cryomodelmotors
http://www.stcu.int/documents/reports/distribution/tpf/MATERIALS/TPF/SI_4_06eng1%2025.pdf
Everything has a cost. ;->
L.
"All those who believe in psychokinesis, raise my hand." - Steven Wright
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You know, I get really tired of "Electric Evangelists" sniping at every post the concerns gas powered issues. WE GET IT! Electrics work really well, probably the wave of the future. But some of us like internal combustion engines and the challenges that go with using them to power our planes. So pleese, if you have nothing apropos to contribute to the subject, move on! R%%%% As far as the high price of dope goes, isn't spending money the best part of the hobby? LL~
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You know, I get really tired of "Electric Evangelists" sniping at every post the concerns gas powered issues. WE GET IT! Electrics work really well, probably the wave of the future. But some of us like internal combustion engines and the challenges that go with using them to power our planes. So pleese, if you have nothing apropos to contribute to the subject, move on! R%%%% As far as the high price of dope goes, isn't spending money the best part of the hobby? LL~
Right on, Pete!
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I have yet to see a 20 point finish with Krylon paint.
Larry, Buttafucco Stunt Team
F2B doesn't have appearance points
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F2B doesn't have appearance points
The above quote is pretty much a non-sequitur.
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To quote a well known stunt guy, "our real hobby is spending money". So enjoy !!! :##
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To quote a well known stunt guy, "our real hobby is spending money". So enjoy !!! :##
Yup!
All seriousness aside, is there any other paint chemistry that will do what butyrate does with respect to filling wood, attaching & tightening up covering & such?