Ask Sparky

[RC Storick]

https://www.youtube.com/c/Stunthangar

[Motorman]

Why the profanity?

[RC Storick]

Why the profanity?

Humor

[Avaiojet]

Sparky,

I'm thinking back and I don't remember if you had info on just applying clear cope on balsa prior to attaching covering?

I'm still having some difficulty applying layers of dope on balsa.

Was there a video on that subject?

Charles

[Dane Martin]

I like this new question and answer videos idea Robert. Thanks man!

[Jim Dincau]

Is there a current schedule for the live stream both SH and CLC? Also do you start with nitrate and switch to butyrate after primer or use butyrate from the start?

[john e. holliday]

Sparky,

I'm thinking back and I don't remember if you had info on just applying clear cope on balsa prior to attaching covering?

I'm still having some difficulty applying layers of dope on balsa.

Was there a video on that subject?

Charles

 
Your dope is not thin enough.   You want it thin enough to soak into the wood.

[Motorman]

Here's a question, do you have to have a hollow prop to win the nats?


MM

[Jim Carter]

     Would you rather have all farts be silent but EXTREMELY deadly, or all farts be harmless but EXTREMELY loud?   
(You said to ask ....! ) 

[Doug Moon]

Here's a question, do you have to have a hollow prop to win the nats?


MM

Nope.

[Avaiojet]

 
Your dope is not thin enough.   You want it thin enough to soak into the wood.

John,

I reduce the dope 50% with dope thinner.

I still get brush drag.

Charles

[Mark Scarborough]

John,

I reduce the dope 50% with dope thinner.

I still get brush drag.

Charles

the quantity does not matter, the results do,
if you get drag, you are workig the dope to long, or its not enough thinner
doesnt matter if its 30% or 70 %,, especially since what brand and the age of the dope can come into play,,

[Randy Cuberly]

John,

I reduce the dope 50% with dope thinner.

I still get brush drag.

Charles

Charles there are a couple of schools of thought (and action) on applying dope to wood structures.  One group (probably the largest) is like Doc and says to thin the dope 50/50 as you do.  The other group says to apply the first two or three coats straight from the can.  I've done it both ways and now subscribe to the latter as being better for adhesion of the covering material.  If you are getting brush drag my first guess is that you are not using enough dope on the brush.  The dope should flow from the brush in strokes from one direction only and as dope drys very quickly (especially with a lot of thinner in it) do not repeatedly brush over the same spot without adding dope to the brush.  It's actually more of a process of flowing the dope onto the surface than brushing it into the surface.  Of course as I'm sure you know, lightly sanding between each coat helps the subsequent coats penetrate better also!

Like you I'm interested in hearing what Sparky has to say about this also!

[Mike Griffin]

Randy you beat me to it.  I learned a lot about dope finishing a long time ago from Charlie Reeves.  He told me to apply the first coat of nitrate  to the wood airframe straight from the can and I do.  I then put two more coats on after tha thinned 50/50.  I then apply the Polyspan around the edges with thinner only.  He also suggested when using Polyspan on open bays to apply that first coat straight from the can to fill the Polyspan quicker and then follow up with 50/50 subsequent coats.  It is not unusual for me to apply 8-10 coats of 50/50 thinned dope to fill the Polyspan before priming and then color.  Yes brush in one direction only.  I sometimes forget and brush back...I'm human.

Mike

[Avaiojet]

Gentlemen,

Thanks for the information.

That's what I forgot, to brush in one directon only.

Thanks again,

Charles

[Howard Rush]

That's what I forgot, to brush in one directon only.

Applies to cats.

[Howard Rush]

Nope.

That was then.  This is now.

[Howard Rush]

Nope.

You might be able to make up for it with enough VGs.

[Randy Cuberly]

You might be able to make up for it with enough VGs.

If you can get them all to stay on the wing for a whole flight!   

I can tell you that they are effective because funny things happen when they all come off only the inboard wing!   

Randy Cuberly

[wwwarbird]

Applies to cats.

 Bazinga! 

[wwwarbird]

 Where are we supposed to be to ask questions?

[CircuitFlyer]

What works better on cats - nitrate or butyrate?

[Mark Scarborough]

What works better on cats - nitrate or butyrate?

I think its the VGs

[RC Storick]

ask here or in youtube video

[RC Storick]

https://www.youtube.com/c/Stunthangar

[wwwarbird]

 A perfectly timed new video here as I'm almost ready to start shooting color on the current project, thanks!

 I did use DC540 for the first time on this one and so far I really like the stuff, it dries super fast and sands very nicely. So far this is shaping up to be my smoothest finish ever. As long as I don't have any adhesion issues through the masking and color process I'll be sold, just have to remember to use plenty of thinner. I do wish I would have caught the "tape off the open bays" tip with the primer first though, oh well.

 BTW, when you say 60/40 are you meaning 60% clear or 60% thinner?

[RC Storick]

A perfectly timed video there as I'm almost ready to start shooting color on the current project, thanks!

 I did use DC540 for the first time on this one and so far I really like the stuff, it dries super fast and sands very nicely. So far this is shaping up to be my smoothest finish ever. As long as I don't have any adhesion issues through the masking and color process I'll be sold, just have to remember to use plenty of thinner. I do wish I would have caught the "tape off the open bays" tip with the primer first though, oh well.

 BTW, when you say 60/40 are you meaning 60% clear or 60% thinner?

60% thinner 40% dope

[bill bischoff]

Applies to cats.

Do you paint ON the cat or WITH the cat? I suppose if done properly, your finish will be the cat's meow.

[wwwarbird]

60% thinner 40% dope

 That's what I thought, thanks.

[Perry Rose]

If you paint with the cat, the cat will meow( if you get to close to the bung and if that happens the cat will finish your face) and the finish will be the cat's pajamas.

[mike londke]

Who makes the DC540 and where can I buy it? Another dumb question but I'm assuming you can put colored dope over this primer? Is it compatible with Sig, Brodak And Randolph?

[RC Storick]

Who makes the DC540 and where can I buy it? Another dumb question but I'm assuming you can put colored dope over this primer? Is it compatible with Sig, Brodak And Randolph?

Sherwin Williams and it's only sold at NAPA auto. You can use any paint over it.

[wwwarbird]

Who makes the DC540 and where can I buy it? Another dumb question but I'm assuming you can put colored dope over this primer? Is it compatible with Sig, Brodak And Randolph?

 It comes in a rattle can and DC540 is the NAPA part number. My local NAPA has it right on the shelf. As a note the stuff can be "watery" and run easily if you get in too close while spraying, and also not cover well. Just stay back slightly to be spraying it out somewhat "dry" and it works great. My only real complaint so far is that one can doesn't seem to go very far. When you stop to get some buy at least a couple cans and you might save yourself another trip.

[mike londke]

Thank you guys. I'll try it out on the next model.

[Sean McEntee]

Question:

          Since cats always land right side up, and buttered toast always lands upside down, can we combine the two and, using the opposing forces, create enough energy to power everything forever?

[Randy Cuberly]

Question:

          Since cats always land right side up, and buttered toast always lands upside down, can we combine the two and, using the opposing forces, create enough energy to power everything forever?

Sure, just figure out how to get the cat inside the toast!  Yes that's the cat inside the toast!

Randy Cuberly

[Air Ministry .]

Perhaps;

form a Special Comitte & aply for Government Funding !

DOPE : using sting little on ounce bottles and a weeny brush , or putting on with a dryish brush anyway
as opposed to ' loading ' a brush and slopping on & brushing out - so 4 or 5 wettings with a 1 1/4 wide
x 2 in long brush do a sheet of 3 x 36 in , are differant .Weve Found .

Doing it like our painting say a window frame with house paint rather than ' just ' covering the wood with minimum Qty
seem to affect the Bond.

[rich gorrill]

Hi Sparky, how about a short video on fillets. I'm not sure if you covered this on another post. What makes the best fillets, how do you apply and finish them? what product is easiest to sand?

Rich

[Rick Bollinger]

Read about polyspan tried it on my last project and gave up and used silkspan instead. Going to try it again on my vector. I have 3 nice coats of Randolph Non Taughtning on the framework. Do I need to use Taughtning over the bays after shrinking to keep it tight or the heat alone and use the non taughtning. Thanks Rick

[wwwarbird]

 Rick,

 Polyspan can be a little tricky if you're not used to it. Be patient though and work carefully and once you get the hang of it you'll never go back. As far as the dope goes I've always used taughtening all the way through from start to finish. I've never felt the need to use non-taughtening on anything, anytime, ever.

[john e. holliday]

I agree with Wayne.  Use taughtning from start to color coats.

[Rick Bollinger]

Wow ok will use it the rest of the way. I always have with silkspan but I figured with polyspan non taughtning was the way to go.
Thanks