Re: Is anyone interested in discussing butyrate dope?

anm2 Sun Oct 20, 2013 1:53 pm

I would like to re-furbish an old airplane. Is there a good way to strip old dope off of the plane, or can I just paint over it? Thanks, Andy

roddie Sun Oct 20, 2013 3:29 pm

Hey Andy, Are you painting the same color? Did you paint the original finish? Does the model have "built-up" structures? If so; their "covering" may be VERY fragile (paper/silk-span "more-so" than silk cloth) I don't know a whole lot... but I would check a paint/dope compatibility chart. Butyrate over Butyrate would be fine... but Nitrate (over/under???) Butyrate could be an issue. I didn't read this whole thread... but one type is not compatible with the other... I'm not sure which and under what circumstances.

Starting with a small area on the (inconspicuous) fuse's bottom, I would "lightly and carefully" sand as much paint off as possible, using very fine sandpaper. If someone else painted the model, you need to find out what's under the finish. If it becomes obvious that a "primer-coat" color is observed, you could then elect to sand most of the "finish" color off; down to the primer. This is a lot of work... but will pay-off HUGE in finish-weight and thus... flight performance. It will be a lesson in patience... open framework areas may have "age-brittle" covering that can be punctured with discouraging ease... especially if they are of the "paper-type" covering.

After final finish-sanding and a "day or so" prior to re-painting; make sure your work area is dust free (especially if spraying-on the finish). Wipe the entire model down with a tack-rag, to remove any dust "immediately before" you apply the first coat.

Whenever I am painting or "gluing" indoors... I place a fan (on low speed) a "distance" behind me and a 2nd one in an open window in "front" of me if possible. A small "utility"room is good... and the model can stay in there while the finish cures with the door shut and fans running... (weather permitting)

Hope that this has been some help. Good luck! Take photos!

Roger

SuperDave Sun Oct 20, 2013 4:52 pm

Dollar fordollar, butyrate finishes are multiples of synthetic fininshes by the time you buy thinner, retarder and other specialized products needed. (Butyrate but be thinned at least 3 part thnner to one part butyrate and then there's having the knowledge and spary equipment to apply is satisfactorilly.

Done by an accomplished pro like Windy Wutowski (sp?) at Brodak a butyrate finish can be one of the best anywhere otherwise stay with synthetics and save your $$$, time and patience. The fisnished plane will be lighter too.

SD

anm2 Sun Oct 20, 2013 5:29 pm

roddie wrote:Hey Andy, Are you painting the same color? Did you paint the original finish? Does the model have "built-up" structures? If so; their "covering" may be VERY fragile (paper/silk-span "more-so" than silk cloth) I don't know a whole lot... but I would check a paint/dope compatibility chart. Butyrate over Butyrate would be fine... but Nitrate (over/under???) Butyrate could be an issue. I didn't read this whole thread... but one type is not compatible with the other... I'm not sure which and under what circumstances.

Starting with a small area on the (inconspicuous) fuse's bottom, I would "lightly and carefully" sand as much paint off as possible, using very fine sandpaper. If someone else painted the model, you need to find out what's under the finish. If it becomes obvious that a "primer-coat" color is observed, you could then elect to sand most of the "finish" color off; down to the primer. This is a lot of work... but will pay-off HUGE in finish-weight and thus... flight performance. It will be a lesson in patience... open framework areas may have "age-brittle" covering that can be punctured with discouraging ease... especially if they are of the "paper-type" covering.

After final finish-sanding and a "day or so" prior to re-painting; make sure your work area is dust free (especially if spraying-on the finish). Wipe the entire model down with a tack-rag, to remove any dust "immediately before" you apply the first coat.

Whenever I am painting or "gluing" indoors... I place a fan (on low speed) a "distance" behind me and a 2nd one in an open window in "front" of me if possible. A small "utility"room is good... and the model can stay in there while the finish cures with the door shut and fans running... (weather permitting)

Hope that this has been some help. Good luck! Take photos!

Roger

Roger,

The plane was scratch built and finished by me about 35 years ago, as a science project. It sat in my mother's garage after I left for college. I used butyrate dope on the fuse and covering. I probably used SIG dope, but I am not 100% sure. The covering disintegrates to the touch and the paint faded so bad that I can see balsa color through the paint. The plane is in ok shape for 35 years, however, I am tired of looking at the skeleton, and I would like to clean it up. It has sentimental value. I can sand it down, but I wasn't sure if there was an easier or better way. Andy

anm2 Sun Oct 20, 2013 5:35 pm

SuperDave wrote:Dollar fordollar, butyrate finishes are multiples of synthetic fininshes by the time you buy thinner, retarder and other specialized products needed. (Butyrate but be thinned at least 3 part thnner to one part butyrate and then there's having the knowledge and spary equipment to apply is satisfactorilly.

Done by an accomplished pro like Windy Wutowski (sp?) at Brodak a butyrate finish can be one of the best anywhere otherwise stay with synthetics and save your $$$, time and patience. The fisnished plane will be lighter too.

SD

I learned to build using silkspan and dope and I never warmed up to synthetic. There is something about a plane that is finished with dope that I like. I do a good job applying silkspan, but am only fair at painting. I use a brush, not a sprayer. This thread has a lot of good pointers. I will keep at it until I become an accomplished pro like Windy:) Andy

duke.johnson Sun Oct 20, 2013 8:46 pm

I can't believe I missed this thread! I use mostly Randolph dope, nitrate and butyrate both. Nitrate is cheaper, but only good for electric and sealing the balsa/covering before your fuel proof coats. Everything sticks to nitrate dope better, so I've started sealing my planes with nitrate first. Then I cover usually with polyspan, then three coats of nitrate, sanding between coats. After that comes the butyrate color dope and finish with butyrate clear.

Brodak does use Randolph dope, but I don't remember if it's non-tautening or not, or if they carrier both. I've used Brodak, especially if I want small amounts. I usually buy from Spencer Aircraft at the airport in Puyallup, Washington, I think you can buy from them online also. I buy the non-tautening dopes. I brush the first coats of clear then move to the spray gun when I start the color.

Doping a plane always cost more than film and always takes longer, but the look so good when finishes. I usually only dope planes in the summer, wet and humid weather will make the dope blush (which takes more time). When painting balsa it will look better if you cover the balsa first, way nicer/smoother finish. You could never make a plane look as good with film.

Kim Sun Oct 20, 2013 10:29 pm

I grew up using Aerogloss, and still use Mr. Brodak's products (with some Randolph's thrown in). I'm by no means close to being an expert finisher, but truly love peeling away masking tape to see my plane come to life. Monokote is also great, but doesn't make the shop smell nearly as "Airplaney" !

Is anyone interested in discussing butyrate dope? - Page 2 Winder10

Is anyone interested in discussing butyrate dope? - Page 2 Winder11

Is anyone interested in discussing butyrate dope? - Page 2 Winder12

Is anyone interested in discussing butyrate dope? - Page 2 1810

Is anyone interested in discussing butyrate dope? - Page 2 1_110

Is anyone interested in discussing butyrate dope? - Page 2 Mambo_10

roddie Mon Oct 21, 2013 2:53 am

Love the "Winder" Kim!!! I was given some old kit-boxes with scrap-wood and plans years ago... along with some partially built planes. I have the "Winder" box/plan... and possibly the wing.

I also have the "Voodoo" box/plan... I've always wanted to scale the "Voodoo" down for a 1/2A reedie. I think the plan is half-scale (18 in. w/s)... maybe too small.

any thoughts on this?

Kim Mon Oct 21, 2013 4:32 am

Thanks Roddie!

How about a 1/4A Voodoo ???!!!!! A Tee Dee .020 might pull it along pretty good at 18" !!!

SuperDave Mon Oct 21, 2013 11:49 am

"Brewing" butyrate dope for application involves an "alchemy" few seem to have mastered nowadays save for the likes of Windy W. of Brodak fame.

My attempt on my BRM was satisfactory at best.

SD

duke.johnson Mon Oct 21, 2013 12:01 pm

What I find helps a lot is thinning the dope to at least 60/40, thinner/dope. The dope is to thick 50/50 to brush without leave brush marks. And to spray, some colors seem to need a little more thinner, depending on the spray gun I use and the color of dope. Like white, it has way more pigment and needs more thinner.

RK Flyer Mon Oct 21, 2013 12:33 pm

I am building now & ready to cover my 1st plane with dope, soooo I ve picked up "Eze Dope" (cleans up /water), Sig Super Coat paint (Brush On-Butyrate) and some Paint Thinner from the Hardware store.

I tried some PolySpan paper on a scrap piece / full strengtj dope & its ok so I'll try some with the thinner at 50/50 or 60-40 and see what happens next.

This forum is a huge help for me! RK Flyer Flying

SuperDave Mon Oct 21, 2013 12:36 pm

Duke:

I have no problen with what you wrote about butyrate application. What concerns me is the expense involved: thinner, retarder etc. which are fully as expensives the butyrate itsel by volume. You may cosider me a "cheapskate" but I build to fly rather than win "best finish" competitions.

When old-fashioned Aero-gloss was still available I could, and did, produce models with great finishes at an affordable price. My Old Kenhi "Cougar" built in 1962 is an example.

But that was then and this is now. I've always built with the assumption that all, save for a very few airplanes will eventually irrepairably crash.

Kim may enjoy the butyrate aroma but, like Crown Royal, I choose to go a less-expensive route to achieve a finish of which I can be proud.

SD

duke.johnson Mon Oct 21, 2013 1:19 pm

Super Dave
I'm not sure we disagree, I think a dope finish cost more than film. But I also think it is a nicer looking finish. I to am more interested in a well flying plane over the beauty queen, but Im always trying to improve my building and finishing skills. I usually cover with film in the rainy seasons and dope in the dry season. For all those who aren't in Western Washington and SD and I, notice the underlines. We have three rainy seasons and one dry season. lol!

Dope finishes are more work and cost more, but they are so nice when done. Covering in film is another art and maybe another topic.

roddie Mon Oct 21, 2013 1:49 pm

SuperDave, My Dad was/is a "Silk and Dope" finish guy. He's only built a handful of planes. (and none in the last 25 years) His last model was a GORGEOUS Sterling "Monocoupe"... which was actually his "first attempt" using iron-on covering. It is "white" MonoKote with red trim.

By comparison, my "Uncle" threw a "Stunter" together in the time it took the Ambroid and Clear dope to dry. "Build it... fuel-proof it, and fly it" was his style.

It's always a gamble... flying a model airplane... you only need to ask yourself how you'll feel; if the unthinkable does happen, and you're picking up lots of pieces of broken airplane off the ground... probably not too bad if you had 20 or 30 hrs. invested in building/finishing... but real bad if you had 100...

A beautifully finished model looks great standing still... or hanging in the hangar... Having fun with it, is what's most important IMHO.

duke.johnson Mon Oct 21, 2013 3:24 pm

Roddie- I agree, having fun with your model is very important. I think building the model is part of the fun though. I for one enjoy building more than flying, my oldest son loves to fly and hates to build. I also want my building skills to improve with my flying skills. I don't think that has happened in my case lol!

. But someday I'll (hopefully) fly better and the planes will last longer, and I'll have a beautiful plane to fly all the time. Everyone had a different take on this vast modeling hobby. Some like film, some dope finishes, some just want to fly and never build. In the rainy seasons, I try to improve my film covering skills. And in the dry season, I try to improve my doping skills. Then when I get a chance to fly I try to improve the flying skills (lost cause I'm afraid) lol!

SuperDave Mon Oct 21, 2013 4:45 pm

Duke:

The only way to improve your flying skill is to crash a few airplanes. They are inseparable parts of the same equation it seems. Laughing

Just so you learn from the experience.

I learned to do this on my Real Flight sim. For every crash that I experience I REQUIRED myself to write the reason (which was most often "pilot error) before I hit the reset button to continue.

SD

roddie Mon Oct 21, 2013 5:22 pm

Does "Aero-Gloss" Butyrate dope have a shelf-life? Can it be "thinned" with other thinners? I have a couple qts. of clear, and several 1/2 pint glass-jars of assorted colors, sanding sealer and fuel-proofer. I probably have a "pint" (maybe a little more) of Aero-Gloss thinner.

Kim Mon Oct 21, 2013 5:39 pm

I was never able to get it to work with anything else, but my experience is rather limited. Several years ago, I was told by my local hobbyshop guy that they changed their own formula, and it would not mix with older Aerogloss...but again, don't know this as fact....

duke.johnson Mon Oct 21, 2013 6:08 pm

I've never used Areogloss. My local hobby shop owner just gave me a whole box of Areo gloss in rattle cans though.

andrew Mon Oct 21, 2013 6:22 pm

Kim wrote:I was never able to get it to work with anything else, but my experience is rather limited. Several years ago, I was told by my local hobbyshop guy that they changed their own formula, and it would not mix with older Aerogloss...but again, don't know this as fact....

I've heard the same --- that Aerogloss was the least compatible with other formulas.

roddie wrote:Does "Aero-Gloss" Butyrate dope have a shelf-life? Can it be "thinned" with other thinners? I have a couple qts. of clear, and several 1/2 pint glass-jars of assorted colors, sanding sealer and fuel-proofer. I probably have a "pint" (maybe a little more) of Aero-Gloss thinner.

I not aware of a specific "shelf life", but the biggest problem is evaporation of the volatiles, particularly from containers that have been opened. Even unopened containers, especially glass jars with a metal lid, are prone to "drying" out. I expect that the gasket material, usually some type of cardboard, allows the solvent to gas off over time. I have had some luck slowing the evaporation by pouring a layer of acetone on top of the dope before sealing. If the can is metal, like the pints and quarts that SIG shipped, I will usually store the can upside down to keep the dope from skinning over.

andrew

pkrankow Mon Oct 21, 2013 7:00 pm

I have used dope brushes left for years dried and hard by dipping in the correct thinner for a couple minutes then back into the correct color.

Dope is pretty crazy stuff.

Phil

roddie Mon Oct 21, 2013 7:48 pm

Here's my Pactra stock. The "Barbie's Plane" was painted with the "rattle-can" International Orange in 1993... and still looks bright and glossy.

Is anyone interested in discussing butyrate dope? - Page 2 Aerogl10

Is anyone interested in discussing butyrate dope? - Page 2 Aerogl10

Is anyone interested in discussing butyrate dope? - Page 2 Barbie14

roddie Tue Oct 22, 2013 12:15 am

roddie wrote:Love the "Winder" Kim!!! I was given some old kit-boxes with scrap-wood and plans years ago... along with some partially built planes. I have the "Winder" box/plan... and possibly the wing.

I also have the "Voodoo" box/plan... I've always wanted to scale the "Voodoo" down for a 1/2A reedie. I think the plan is half-scale (18 in. w/s)... maybe too small.

I did some digging around this afternoon...

Is anyone interested in discussing butyrate dope? - Page 2 Plans-10

Is anyone interested in discussing butyrate dope? - Page 2 Kit_bo10

Is anyone interested in discussing butyrate dope? - Page 2 Kit_bo11

Mostly "parts storage" boxes except for the "Nobler"... there's a complete un-built kit in that box.

RK Flyer Thu Oct 24, 2013 12:07 pm

Ok I've finished with the poly span tissue and I have some sanding to do before I start with the color paint. I'll be using Sig Super Coat in Black , Grey & White and brushing it on.
Sooo what kind of Brush is good? I have Foam & regular bristle. Should the color paints be thinned? Any other tips?

RK Flyer Flying

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Is anyone interested in discussing butyrate dope?