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Building Tips and technical articles. => Building techniques => Topic started by: Phil Goldberg on February 28, 2017, 11:14:55 PM
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I understand that Nitrate will not go over Butyrate. However am I wrong to think that Butrate Thinner and Nitrate Thinner are the same thing?
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I quit using Nitrate anything years ago after messing up a finish one time. But, then again I've never seen a can marked Nitrate Thinner. ???
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Doc, look at Brodaks web site and you'll see Nitrate Thinner.
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Phil...not an expert but I have always used DOPE thinner for both
Many will claim Lowe's or similar cheap Lacquer thinner is good enough stuff...others believe DuPont 3608 variants are good enough
But I prefer to reduce any possible problems, so use always same brand thinners for thinning ----and I do use the much cheaper Home Depot stuff to clean guns and brushes
As far as I know Nitrate and Butyrayte both use the same thinner
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Randolph (now owned by Certified from what I have been told) product list shows both nitrate thinner and butyrate thinner. So, I would have to assume that each has to be used with the intended dope. I have not tried using nitrate thinner in butyrate dope, nor have I tried using butyrate thinner in nitrate clear dope, so I can't tell you what would happen if you did.
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OK I forgot...when I went to the supplier in Dallas Tx for my Randolph dope-- they did have both thinners... But I asked and the counter guy said the Butyrate thinner is good for both dopes but Nitrate thinner should ONLY be used in Nitrate Dope
Like many others I have stopped using Nitrate dopes and now do everything with taught and Non taught Butyrate dope
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I suppose a call to the dope manufacturer would clear up any questions about compatibility. Even so, I think I will stay with nitrate thinner in nitrate clear, and butyrate thinner in butyrate dope. I doubt if I will use nitrate under butyrate anymore. I tried it once, had some issues with the butyrate not looking right. There were "lumpy" areas, it did not flow out well and level well. I have no idea what went wrong but from now on I will stay with all butyrate.
I recently bought another quart of Randolph clear non-tautening dope from a local aircraft supplier. I did not pay any attention to the label until I got home and saw a logo for Consolidated Aircraft Coatings on the label, along with the Randolph name.
The clear dope has a bit of amber tint to it. Not much, but the "Randolph" brand (without the Consolidated logo on the label) looked to be without such a tint.
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Fredvon has it right. Butyrate thinner works in both nitrate and butyrate dope. Nitrate thinner should only be used in nitrate dope. As far as amber color goes, I don't know what causes it but suspect that it is age related. I have seen it in Sig dope as well as the brands you mention. I use it anyway but not for final clear coats. 8)
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Fredvon has it right. Butyrate thinner works in both nitrate and butyrate dope. Nitrate thinner should only be used in nitrate dope. As far as amber color goes, I don't know what causes it but suspect that it is age related. I have seen it in Sig dope as well as the brands you mention. I use it anyway but not for final clear coats. 8)
I have noticed that the degree of amber tint varies. The last can I bought should be from the latest lot so I hope the amber tint is not from age.
In the past, I used amber tinted clear for final clear coats. I have not see any undesirable results from using it but over time maybe it shows up as yellowing when used over lighter colors. The Brodak Crystal Clear has no amber tint. But, it has almost zero fuel resistance, at least from what I discovered from some quickie experiments. If raw fuel is not wiped off immediately it will leave a blemish. The gloss will be gone and it looks something like blushing from humidity. I no longer use it for final clear coats.
The Randolph (Consolidated) non-tautening clear appears to hold up to raw fuel a little better.
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I quit using Nitrate anything years ago after messing up a finish one time. But, then again I've never seen a can marked Nitrate Thinner. ???
Brodak has it. ;D
Jerry
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The AMBER TINT in my gallon of Pheonix ( Aus . ) Nitrate Dope
is now sitting in lumps in the bottom of the can.
If you accidently hit one using the paint brush , you get smears of it in the thing your attacking with the paint brush .
The Butrates suposed to be not so hot for tissue on fillets , or adhearance . Which means it strips of far easier for recovering .
This nitrate dosnt gloss up like butrate . Just about had it with it, too .
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Phil -
I , likewise, was always told that nitrate could not be used over butyrate. I recently got a copy of Tom Dixon's 'Controlline World' construction articles. In one of his acticles on finishes, he states that, indeedd, nitrate can be applied over butyrate, and does. I decided to try it on my current project, and had no issues with compatability. In fact, I sprayed the entire plane with a coat of nitrat over butyrate. Looked good, except for a satin finish. Anyway, be sure to cover the nitrate with butyrate, since the nitrate has issues wth resistance to fuel.
Brew
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I just opened a new gallon of Randolph Clear Butyrate and it has the amber tint. I went back to the Aircraft Spruce website and with a little searching found you can still get the non tinted version. What you want is A-1690 Butyrate Dope, Non-Tautening (CLEAR). It says right in the description for use over non-tautening Nitrate where tinted dope is not desired, also says thin with 9703 Butyrate Thinner. I may have to place another order, I really don't like the amber tint.
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I have been buying the Randolph non-tautening clear, A-1690. I never tried any other butyrate clear from Randolph. The last two quart cans have some amber tint. The most recent can does not appear to have as much amber tint as the previous one. I noticed that both cans with amber tint have the Consolidated logo on the label. The last can I bought without the Consolidated logo had no amber tint. So, getting the A-1690 may not guarantee no tint.
Now that Randolph has been acquired by another company maybe the formulation has changed or maybe the quality control is not what it once was.
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The tints are used to tell butyrate, nitrate, taut and non-taut apart. They might mess things up for clear-coating.
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I understand that Nitrate will not go over Butyrate. However am I wrong to think that Butrate Thinner and Nitrate Thinner are the same thing?
Hi Phil,
Butyrate thinner & nitrate thinner are definitely not the same thing. Nitrate thinner will not work in butyrate dope at all. However, butyrate thinner will work just fine in nitrate dope. While quite a few modelers use nitrate dope I have never found any need to use it on my models. Butyrate dope has plenty of adhesion from the bare balsa on through the final finish & is fuel resistant whereas nitrate has no fuel resistance.
The only place that I use nitrate dope is on full-scale aircraft restorations that are using a covering process that has an STC that mandates the use of nitrate as the first coats down on the bare fabric.
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Phil...not an expert but I have always used DOPE thinner for both
Many will claim Lowe's or similar cheap Lacquer thinner is good enough stuff...others believe DuPont 3608 variants are good enough
But I prefer to reduce any possible problems, so use always same brand thinners for thinning ----and I do use the much cheaper Home Depot stuff to clean guns and brushes
As far as I know Nitrate and Butyrayte both use the same thinner
Do not try to use nitrate thinner in butyrate dope as it will create a mess.
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Randolph (now owned by Certified from what I have been told)<snip>
Randolph is owned by Polyfiber in Riverside at Flabob airport. Polyfiber and Randolph are under the corporate identity of Consolidated Aircraft Coatings.
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Fredvon has it right. Butyrate thinner works in both nitrate and butyrate dope. Nitrate thinner should only be used in nitrate dope. As far as amber color goes, I don't know what causes it but suspect that it is age related. I have seen it in Sig dope as well as the brands you mention. I use it anyway but not for final clear coats. 8)
Hi Pete,
The amber tint is definitely age related and is caused by the dope becoming more acidic with age. The dope will still work up to a point but when it begins to smell differently from fresh dope it should not be used.
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The tints are used to tell butyrate, nitrate, taut and non-taut apart. They might mess things up for clear-coating.
That depends on the tint color...amber tint is not used for dope type identification and is not intentionally used.
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Thanks for the info Bill. I'm on my way out to throw away about a 1/2 quart of amber colored Sig Lite Coat. It does have a different smell then when it was clear...not going to chance it. 8)
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My last gallon of Randolph butyrate clear from Aircraft Spruce was tinted. I'll just use it to build up the finish, under color coats.
That's what it is supposed to be for.
Not worth the trouble shipping it back for an exchange.
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Aircraft Spruce.
Butyrate Dope (Tinted) - Non-Tautening
That is a copy of there add. Does that answer the question about tinting.
http://www.aircraftspruce.eu/covering-supplies/randolph-coatings.html
clear no tint
http://www.aircraftspruce.eu/covering-supplies/randolph-coatings/butyrate-dope--clear----tautening.html
Ed
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The tints are used to tell butyrate, nitrate, taut and non-taut apart. They might mess things up for clear-coating.
Just to help clear (no pun intended) up the use of tint colors in Randolph clear dopes here is a list of the clear & tinted products.
1. Nitrate clear, tautening, #210 No tint, completely clear. Used only on Grade A cotton or Irish Linen (full-scale airplanes since we don't use those fabrics).
2. Nitrate clear, non-tautening, #E-4964 No tint, completely clear. Used on Ceconite or other heat-tautening polyester fabric processes.
3. Nitrate clear, non-tautening, #G-6302 Green tint, recommended for first coat down on Ceconite or other heat-tautened fabric. Has special additives for adhesion promotion on polyester fabric. The green tint enables you to see how much you are applying to the fabric as well as being an identifier of the dope.
4. Nitrate clear, non-tautening, #W-7868 Blue tint, also used for the first coat down on polyester fabric but with only plasticizer added. The blue tint enables you to see how much is applied to the fabric as well as acting as an identifier of the product.
Butyrate also gets a tint on one Randolph product.
1. Butyrate clear, tautening, #9701 No tint, completely clear. Not recommended for use on heat-shrunk synthetic fabrics such as Ceconite (Dacron).
2. Butyrate clear, non-tautening, #W-8350 Light tan tint and dries clear. Again the tint enables you to see how much is being applied.
3. Butyrate clear, non-tautening, #A-1690 No tint, dries clear.
4. Butyrate silver, non-tautening, #G-6303 (Rand-O-Fill) has aluminum pigment to block ultraviolet light to prevent deterioration of the fabric.
All Randolph colored (for topcoat colors) butyrate dope products are non-tautening.
Just thought I'd list it here so that anyone who does not have either a Randolph product sheet or an Aircraft Spruce Catalog can see it directly.