Author Topic: Certified Dope (Read 2048 times)

Jim Damerell · « **on:** December 19, 2018, 09:50:34 AM »

Does anyone have a discount supplier for Certified? At Aircraft Spruce a gallon of non-taunting dope is $75. Taunting is $50, Randolph's either way is $50. I am a bit of a cheapskate, but that $25 difference seems a little high

Alan Resinger · « **Reply #1 on:** December 19, 2018, 01:39:49 PM »

Hi Jim,
Certified seems a bit expensive but when you buy a gallon and open the can you will think that you got a can of molasses. Cox and I split a gallon and we each end up with a gallon and a half. It is so thick you will have to thin it at least 2.5 to 3 parts thinner to one part dope. It is water clear and doesnt yellow with age like Randolph clear does. We figure we get between 3 and 4 gallons from a gallon. It is great stuff.

Avaiojet · « **Reply #2 on:** December 19, 2018, 06:28:49 PM »

Quote from: Jim Damerell on December 19, 2018, 09:50:34 AM

Does anyone have a discount supplier for Certified? At Aircraft Spruce a gallon of non-taunting dope is $75. Taunting is $50, Randolph's either way is $50. I am a bit of a cheapskate, but that $25 difference seems a little high

Jim,

I buy all my clear dope and thinners from SIG in qts.

C

Jim Damerell · « **Reply #3 on:** December 20, 2018, 04:00:13 AM »

Alan,
I know it's great stuff, been using it for years. I just don't remember the non taunting being that much more than the taunting. I was hoping there was some other mystery supplier out there I had not found yet.

Randy Powell · « **Reply #4 on:** December 20, 2018, 01:41:07 PM »

I buy Certified from Spencer Aircraft. Last I bought it (about 6 months ago), it was $64 a gallon and as Alan noted, the stuff is as thick as molasses.

Ken Culbertson · « **Reply #5 on:** December 20, 2018, 04:17:28 PM »

I was curious who this topic's subject referred to but I can see from the postings it is Paint! Whew...

Ken

Dan McEntee · « **Reply #6 on:** December 20, 2018, 05:02:23 PM »

Quote from: Randy Powell on December 20, 2018, 01:41:07 PM

I buy Certified from Spencer Aircraft. Last I bought it (about 6 months ago), it was $64 a gallon and as Alan noted, the stuff is as thick as molasses.

Reading this and also the thread about storing dope makes me wonder. If Certified is that thick, it may last longer in storage. Less solvents to leach out, allowing the dope to harden. Maybe break it down into quarts like this and then break down the quarts into what you need for a model?? If it thins out to where 1 gallon un-thinned turns into three gallons of thinned spayable dope, that isn't too bad SIG dope is pricey these days also at 30 bucks or so a quart for Litecoat non tautening. Maybe some savings by experimenting with plasticizing like they did in the old days. Do some small models and where you want non-tautening dope, hit it with some castor oil, ( a few drops per ounce) and see how it reacts. Dave Brown Products still makes Flex-All, but I really think all it is, is repackaged medicinal castor oil. There is a chemical that is used for it but it is BAD JU JU!! I looked the stuff up once and just looking at the MSDS sheet could give you cancer!
Type at you later,
Dan McEntee

GallopingGhostler · « **Reply #7 on:** December 20, 2018, 06:54:15 PM »

All this talk of clear dope, I bought lightweight 1.1 oz/sq. yd. ripstop nylon in both woodland marpat digital camo and a grayish silver.

I read where some are using these fabrics to cover RC combat aircraft, was thinking I could apply this to my 55 inch span Brodak Fock Wulf FW-190 profile CL warbird, or possibly my 33 inch span Midwest Curtiss P-40 Warhawk profile CL warbird. Although it wouldn't be totally scale, I thought it would be aesthetically pleasing and not be too far off from a desert camo aircraft representation. The silver would be used for the undersides. It would have the appearance of translucence similar to clear doped silk, but with a nice camo showing.

This would be the first time I am trying this.

What clear dope or paint might be suitable to fill the weave of these? They are supposedly water resistant.

BYU · « **Reply #8 on:** December 20, 2018, 10:47:31 PM »

George would you be willing to share where you bought your ripstop Nylon?

GallopingGhostler · « **Reply #9 on:** December 21, 2018, 12:00:16 AM »

Quote from: Bobs your Uncle on December 20, 2018, 10:47:31 PM

George would you be willing to share where you bought your ripstop Nylon?

https://www.ebay.com/itm/Woodland-Marpat-Digital-Camo-1-1-oz-Nylon-Ripstop-Fabric-68-W-Tent-Military-DWR/302631380508

https://www.ebay.com/itm/Silver-1-1-Oz-Nylon-Ripstop-Fabric-62-W-Tent-Camping-Breathable-Military-DWR/302040717948

Randy Powell · « **Reply #10 on:** December 26, 2018, 10:55:56 AM »

I've tried a lot of different fabrics for covering over the years. Never tried rip-stop nylon, though. Interesting idea.

Mike Haverly · « **Reply #11 on:** December 26, 2018, 10:11:04 PM »

Quote from: Randy Powell on December 20, 2018, 01:41:07 PM

I buy Certified from Spencer Aircraft. Last I bought it (about 6 months ago), it was $64 a gallon and as Alan noted, the stuff is as thick as molasses.

Did they start carrying Certified again? I haven't seen it there in a few years.

Alan Resinger · « **Reply #12 on:** December 27, 2018, 07:26:34 AM »

It isn't listed on their website and I know that the last time I was there, they had nothing but Randolph's.

Jim Damerell · « **Reply #13 on:** December 27, 2018, 07:56:43 AM »

Ordered the Certified from Aircraft Spruce last Thursday afternoon, the product arrived Saturday morning. I guess that kind of service is worth something!

Randy Powell · « **Reply #14 on:** December 27, 2018, 11:35:45 AM »

I don't know now. They had it 6 months ago but I just looked and it's no longer on their web site. Guess I'll have to get it from Aircraft Spruce or Phillips. Shame, that.

wwwarbird · « **Reply #15 on:** December 27, 2018, 08:25:39 PM »

Quote from: Alan Resinger on December 19, 2018, 01:39:49 PM

It is so thick you will have to thin it at least 2.5 to 3 parts thinner to one part dope. It is water clear and doesnt yellow with age like Randolph clear does. We figure we get between 3 and 4 gallons from a gallon. It is great stuff.

This is interesting, especially since I might have to order more clear soon. Aside from the normal brand compatibility paranoia, any issues with thinning it with and/or spraying it over Randolph? I'm thinking it wouldn't be a problem.

Mike Haverly · « **Reply #16 on:** December 27, 2018, 11:08:03 PM »

I've used it over Randolph with no problems. I've never had luck putting anything over Sig except more Sig. I don't know what the formula is but it seems to have more solids and builds up nicely. I haven't used it in a few years but if I remember correctly it takes a little longer to gas, nice stuff though.

billbyles · « **Reply #17 on:** December 28, 2018, 03:10:32 PM »

Quote from: Mike Haverly on December 27, 2018, 11:08:03 PM

I've used it over Randolph with no problems. I've never had luck putting anything over Sig except more Sig. I don't know what the formula is but it seems to have more solids and builds up nicely. I haven't used it in a few years but if I remember correctly it takes a little longer to gas, nice stuff though.

I use Sig over Randolph & vice versa; Certified over Sig & vice versa; Randolph over Certified & vice versa and have never had a problem over the years with compatibility on both models and full-scale aircraft. Any butyrate thinner will work in butyrate dope. Certified thinner is the fastest, Randolph is next fastest, and Sig thinner is the slowest drying and I blend the three depending on temperature and humidity.

I restored a Waco UPF-7 for a customer and he requested that I use a color that Sig had (orange). I covered with Ceconite using Randolph clear and Randolph silver paste mixed in the correct ratio with Randolph clear for the silver coats. The Sig orange butyrate went on next followed by Randolph for the topcoat clear. The airplane has never had a problem with the finish.

When I called Sig and ordered three five-gallon pails of Sig orange they said that they did not ship dope in five gallon containers. We talked awhile & they finally agreed to ship it in the five gallon pails. I was told that they do not get many orders for full-scale airplanes.

Dave Hull · « **Reply #18 on:** December 28, 2018, 06:51:56 PM »

Bill,

You should have told them that your kids were learning how to fly and going thru a lot of airplanes. And, by the by, how much would they charge for another 100 Acromaster kits?

That's almost like the billionaire that wanted a better flying scale peanut that would beat a Lacy. So he had someone build a full sized version so that it would be legal in peanut scale contests...or so the story went. So now, if a guy wants to model a UPF-7 he knows he's absolutely to scale if he buys SIG orange. Brilliant!

Divot McSlow

wwwarbird · « **Reply #19 on:** December 28, 2018, 07:47:45 PM »

Quote from: billbyles on December 28, 2018, 03:10:32 PM

I use Sig over Randolph & vice versa; Certified over Sig & vice versa; Randolph over Certified & vice versa and have never had a problem over the years with compatibility on both models and full-scale aircraft. Any butyrate thinner will work in butyrate dope. Certified thinner is the fastest, Randolph is next fastest, and Sig thinner is the slowest drying and I blend the three depending on temperature and humidity.

Pretty much what I was thinking. I've used Sig, Brodak (which I understand is Randolph?) and Randolph back and forth every which way with no problems.
I've never used Sig thinner in any Randolph or Brodak clear or color though. I've always brand matched the thinners, other than using Randolph (branded) thinner with Brodak (branded) color, but supposedly they're both the same product anyway .

Thanks for the info on the thinner speeds between the brands too Bill, I've never even given that a thought, good to know though.

billbyles · « **Reply #20 on:** December 30, 2018, 04:22:36 PM »

Quote from: Dave Hull on December 28, 2018, 06:51:56 PM

Bill,

You should have told them that your kids were learning how to fly and going thru a lot of airplanes. And, by the by, how much would they charge for another 100 Acromaster kits?

That's almost like the billionaire that wanted a better flying scale peanut that would beat a Lacy. So he had someone build a full sized version so that it would be legal in peanut scale contests...or so the story went. So now, if a guy wants to model a UPF-7 he knows he's absolutely to scale if he buys SIG orange. Brilliant!

Divot McSlow

Hi Dave,

The person at Sig that I was talking with on the orange Light Coat dope asked me how many airplanes are you building? It wasn't until I told him that I was restoring a full-scale Waco UPF-7 that he understood why I was ordering 15 gallons and then agreed to package & ship it.

billbyles · « **Reply #21 on:** December 30, 2018, 04:36:48 PM »

Quote from: wwwarbird on December 28, 2018, 07:47:45 PM

Pretty much what I was thinking. I've used Sig, Brodak (which I understand is Randolph?) and Randolph back and forth every which way with no problems.
I've never used Sig thinner in any Randolph or Brodak clear or color though. I've always brand matched the thinners, other than using Randolph (branded) thinner with Brodak (branded) color, but supposedly they're both the same product anyway .

Thanks for the info on the thinner speeds between the brands too Bill, I've never even given that a thought, good to know though.

Hi Wayne,

I have always used butyrate thinner to thin butyrate dope (& for nitrate dope as well although the only thing for which I use nitrate is covering full-scale airplanes using STC'd processes that require nitrate for the first coats down.) I know there are those who have success using lacquer thinner for thinning dope but I prefer to stick with the correct thinners. Larry Fernandez says he uses lacquer thinner but I can't figure out how he uses it with Monokote...

wwwarbird · « **Reply #22 on:** December 30, 2018, 07:56:14 PM »

Quote from: billbyles on December 30, 2018, 04:36:48 PM

Larry Fernandez says he uses lacquer thinner but I can't figure out how he uses it with Monokote...

Randy Powell · « **Reply #23 on:** January 02, 2019, 02:50:27 PM »

I always go with the manufacturers suggest methods. I find that if you use Certified with Certified, you seldom have problems. But others have difference methods. Hey, if it works for you, cool.