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Building Tips and technical articles. => Paint and finishing => Topic started by: Scott Richlen on May 19, 2014, 08:34:21 PM
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Aircraft Spruce offers a silver paste and a Certi-Fill silver for UV protection (and both are extremely expensive, so I am uninterested in buying some and experimenting), but don't offer silver in their list of colored dope. Have any of you made your own silver Certified dope?
Thanks,
Scott
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Aircraft Spruce has Randolph silver butyrate. M-9514-BQ is a quart, M-9514-BG is a gallon.
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Go to an automotive paint store and get a pint of silver without binder. I did that recently and they asked what color silver I wanted. Like all of the other colors there is a lot to choose from. What I got was made by Matrix, fairly inexpensive considering a pint was $25.00 but mixed with clear is almost a lifetime supply. It looks pretty close to B-25 silver.
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Aircraft Spruce offers a silver paste and a Certi-Fill silver for UV protection (and both are extremely expensive, so I am uninterested in buying some and experimenting), but don't offer silver in their list of colored dope. Have any of you made your own silver Certified dope?
Thanks,
Scott
Hi Scott,
I have made a lot of silver dope from clear and aluminum paste for both the full-scale airplanes I have restored in my business and for my models. The Certified silver for UV protection is the same as the butyrate silver you would buy for a color topcoat. If you are making silver dope be sure that you do not overload the clear with the aluminum paste - you should add no more than 4 ounces of silver paste to a gallon of unthinned butyrate dope or you will encounter intercoat adhesion problems. 3 1/2 to 3 3/4 ounces of paste per gallon will do the job & is a lot safer. Mix the aluminum paste with a little butyrate thinner prior to adding it to the unthinned clear or it will take a long time to get the paste mixed with the dope.
That being said, if I am using butyrate silver for the topcoat color I just buy the Randolph silver (M-9514) from Aircraft Spruce (since they are a 20 minute drive from me) to keep it simple.
If you are using the silver for a topcoat color it will look much better (more metallic) if you apply clear on top of the silver after the silver is dry. Do not sand the silver prior to applying the clear or it will not look uniform, showing sanding scratch marks vividly.
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Bill:
My problem is that 4 ounces of paste is all I need as a gallon of silver will last me a long, long time. I may have to try Mike's suggestion and get to the automotive paint store.
I guess I shouldn't have tried switching dopes; but I found SIG to have too little pigment and bad coverage in their whites and creams, and Brodaks doesn't like fuel on it at all. I had read that Certified was better than Randolph's, but they have very limited colors. Seems like I'm always searching for the "magic bullet". Oh well.
And even smarter - I've got three coats of Certified butyrate clear on my newest plane (but shoulda checked on the silver issue first - oh! oh!) :-\
Scott
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Mike:
I went to the Matrix web-site and they have a bunch of different aluminums. Which did you get?
Thanks,
Scott
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I just checked and can't read the number. I know it is "coarse silver" with no other colors added. Since I wasn't worried about matching anything else I didn't pay any attention to the actual color, probably should have. I know it works really well.
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I do the same thing as Mike suggested for all my colors. Just go into the auto paint place and give them a color number, ask them to mix it without clear binder and go home and put in the clear dope. Works a treat.
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Bill:
My problem is that 4 ounces of paste is all I need as a gallon of silver will last me a long, long time.
I guess I shouldn't have tried switching dopes; but I found SIG to have too little pigment and bad coverage in their whites and creams, and Brodaks doesn't like fuel on it at all. I had read that Certified was better than Randolph's, but they have very limited colors. Seems like I'm always searching for the "magic bullet". Oh well.
And even smarter - I've got three coats of Certified butyrate clear on my newest plane (but shoulda checked on the silver issue first - oh! oh!) :-\
Scott
"My problem is that 4 ounces of paste is all I need as a gallon of silver will last me a long, long time."
OK, so mix 1 ounce of paste with a quart of clear.
"I had read that Certified was better than Randolph's"
In many years of using both Certified and Randolph I have never found that to be true. They are equivalent in quality and are completely compatible with each other.
"(but shoulda checked on the silver issue first - oh! oh!) :-\"
So just buy a quart of Randolph M-9514 Silver which shows as $22 in the latest Aircraft Spruce catalog (price may vary some, look at their website for latest pricing.)
Another thing about butyrate thinners - I have found Certified thinner to be the fastest drying, Randolph the next fastest drying, and Sig to be the slowest drying. I occasionally blend thinners to achieve the drying rate I need.
As far as different colors of silver, on my paint mixing system there are three different silvers differing in the size of the metallic flake. Different colors of silver are made by adding tint colors to the metallic silver - adding just a bit of black to the blue (there are several different blacks, by the way: black to the blue, black to the yellow, black to the green, pure black, etc.) If you are tinting the silver and you want to have the maximum metallic effect then use a semi-transparent tinting color. For instance, adding straight white tint to metallic silver greatly diminishes the metallic effect.
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Randolph bought Certified several years ago. There's no reason for them to be incompatible, just stick with the same thinner in all brands. D>K Steve
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Mike, Bill, Steve:
Thanks for the guidance. I'll follow it.
Scott
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After checking the prices at Aircraft Spruce, I will be going with Randolph for all my clears and colors..............
BIG Bear
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