ironing silver

[wadecalvin]

I just got my second coat of silver (stits polyfiber process) dried on the elevator I'm covering and noticed some air pockets on the bow that I somehow missed when ironing the imperfections out before applying any silver.

Can I iron these bubbles out now with two coats of silver already applied? Dont know how I missed them- I went over it with a fine toothed comb.

 

[wadecalvin]

I just got my second coat of silver (stits polyfiber process) dried on the elevator I'm covering and noticed some air pockets on the bow that I somehow missed when ironing the imperfections out before applying any silver.

Can I iron these bubbles out now with two coats of silver already applied? Dont know how I missed them- I went over it with a fine toothed comb.

I found this answer on the Polyfiber web site: tinfoil over Iron as sheild. glad I didn't just iron it.....

The edges of my finishing tapes are curling up as soon as I spray on Poly-Spray. What should I do?

>You must be careful when fixing this problem. The edges of tapes should have been ironed down after the Poly-Brush was applied. Now you must be careful smoothing them. Use an iron calibrated at 225 degrees F along with a piece of tinfoil as an ironing shield. Do not touch the iron directly to the Poly-Spray. It will leave unsightly marks.

 

[Steve Pierce]

Use parchment paper to lay on the fabric before ironing. The bakery has it. Allow it to cool before removing or it will pull the finish off down to the raw fabric. The chemicals in the Polyspray soften the Polybrush and curls the pinks up. I know how you feel on the bubbles. Everything is a lot more noticeable in silver than in color.

 

[bob turner]

I just iron it and put up with the iron marks in the silver. Once fixed, wet sand and re-coat the spots with silver. You really cannot get enough silver on the pinked edges anyway - you do not want to see zig zag daylight through the fabric. I have never seen a cover job without flaws that don't show up until silver.

No matter what, don't sand that last coat of silver, and make sure you look through an inspection area in full sunlight.

Opinion - maybe Steve's way is better.

 

[Steve Pierce]

Bob, Have you ironed Stits (Polyfiber)?

 

[bob turner]

My very first cover job was Stits in 1968. The tail surfaces still hang in my hangar, and are still airworthy. Yes the iron makes a mess of the silver, but I found that it doesn't happen everywhere. I do iron the pinked edges after the second clear coat, Butyrate or Stits. That way it is only an occasional edge that pops up.

Stits is good stuff, but it is about twice as expensive as the entirely satisfactory Nitrate/Butyrate, and anyway I am sort of put out with one supplier grabbing it all and doubling the price. I will be trying a control surface with Stewarts.

 

[Steve Pierce]

The parchment paper works real well on the silver and doesn't leave a crater in your finish. I am doing a J-3 wing in dope right now and am not sure on your analogy on cost. Takes a lot more reducer than 50% to get it to come out of the gun and I don't see any reason to spray 3 coats of clear dope. I agree with you on the monopoly. I too am about to try the Stewart's System. Polyfiber/Randolph is real good at blaming the FAA. That is why you have to use their finish coat and the reason they can't amend their STC to use either fabric on either system even though they admit it is all the same except for the stamp. I ordered the amount of fabric they called out for wings and ailerons. After covering the aileron and then one side of the wing I wasn't very happy when I rolled the rest of the fabric out on the other side of the wing and it was too short. I was really unhappy when one near by distributor wasn't available and the other doesn't stock Ceconite. I won't tell you what I did, but it was on the recomendation of Polyfiber/Randolph after a long conversation and a bunch of measurements of a J3 wing and aileron relayed to them. :x

 

[wadecalvin]

Thanks guys for the help and taking time to answer this post. I used tin foil and it did have a tendency to stick (should have let it cool per
Steve) and then I tried the edge of the bare iron and didn't do too bad- a little sanding and another coat of silver and at least the bubbles are gone. Doesnt look too bad. Thanks again.

 

[bob turner]

My experience with Stits: I loved the way the Poly Brush ironed. Dope is not quite as nice. I was young, foolish, and broke, but bought their recommended materials. I had about six gallons of Poly stuff left over. The silver was full of little particles; it made my life miserable while spraying, and it wasn't until years later that I finally got a smooth finish.

Dope thinner is lots less expensive than thinned Poly stuff, and you really do not need to use that much dope. Enough Nitrate for the Butyrate to stick to, enough silver to keep the sun out, one coat of white, and two coats of yellow will make a nice Cub. Last time I bought thinner it was $25/gal, and I think thinned Poly stuff is more than that.

 

[AntiCub]

I managed to iron down a couple small spots after the silver using a teflon coated hobby iron and very very little pressure. Didn't seem to try sticking to the poly like a bare metal iron does. It still left a little shiny spot in the finish through.

I'm with Steve, I'm going to use Stewart's next, if only because I hate getting a hangover when I didn't even drink. :-?

Phil

 

[charlesf]

I am just finishing up the wings and control surfaces with Stitt's. I found that the iron will smooth the rough spots and reattach the tape edges very nicely. 225 is the key temperature. I also used the edge of the iron so as not to stick to the silver. It's been many years since I used ceconite with nitrate/butyurate, and the Stitt's seemed easier.
One other item. I went to a HVLP gun on this project. Stitts calls for 2 gallons of color per wing, plus more for the flaps and ailerons. With the HVLP gun, instead of an airgun, I used one half gallon of color for the 6 coats(3 cross coats) on one wing, one aileron, and one flap. That is quite a savings at $200 a gallon.

 

[bob turner]

One more comment before this thing drops off the daily list - When I did my first cover job the Stitts fluids were five and eight bucks a gallon. I think it was the silver that was $8. Already thinned, so I could avoid buying thinner. Gas was 50 cents a gallon for 80 oct. and charts were 35 cents each. As I recall, a loaf of whole wheat bread was a quarter.

Gas is now five bucks a gallon - a ten-fold increase. Charts are eight bucks or so - maybe 23 times as much. If thinned Poly Spray is $200, that is an increase of 25x. Does that mean that avgas is now cheaper in terms of constant dollars, or is Stitts ripping us off? Un-thinned Randolph is still under a hundred bucks a gallon, and thinner is, I believe, under $30.

 

[NimpoCub]

Here is the real cost of poly-stuff as of this summer:

I paid to AC Spruce:
AN Blue - $85/gal
Juneau White - $77/gal
Reducer - $40/gal

Of course I had to pay import/trucking/taxes on top of that.

From a BC retailer:
Polybrush - $105/gal
Polyspray - $$105/gal
Reducer - $72/gal.

NOTHING cost $200/gal, so ya haft'a redo your math

 

[bob turner]

I was just using charlesf's figures. I don't buy Stitts anymore.

 

[charlesf]

Your replies got me to thinking. Sometimes I miscount. Anyway I dug out the invoices from Stoddard's where I get most of my stuff.
Three quarters of a gallon of Aerothane: $130
One quart of catalyst: $55
One gallon of reducer: $60
I think that goes over $200/gallon.
Anyway it's pretty stuff, and really shines.