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Building Tips and technical articles. => Paint and finishing => Topic started by: Tim Wescott on May 15, 2023, 02:23:47 PM

Title: Dents in silkspan/dope
Post by: Tim Wescott on May 15, 2023, 02:23:47 PM
So, I put some dents into my nice doped wing.  The picture makes them look better than they really are.  This is silkspan over an open bay, painted with Sig & Certified butyrate dope, bottom to top.

Is there a way to take the dents out?

(https://stunthanger.com/smf/scale-models/ercoupe-build-(slow)/?action=dlattach;attach=343224;image)
Title: Re: Dents in silkspan/dope
Post by: Ken Culbertson on May 15, 2023, 03:23:57 PM
My finishes are not anything to write home about, or anywhere else for that matter, but I have "sort of" removed some dings by injecting a very small amount of water under the ding then using a monokote iron to heat it.  Got the idea from removing benchmarks in raw balsa before covering.  Dings in polyspan respond to heat as well, as does MonoKote.  Plan "B" is a well-placed decal over the Boo Boo.

Ken
Title: Re: Dents in silkspan/dope
Post by: Tim Wescott on May 15, 2023, 06:08:00 PM
My finishes are not anything to write home about, or anywhere else for that matter, but I have "sort of" removed some dings by injecting a very small amount of water under the ding then using a monokote iron to heat it.  Got the idea from removing benchmarks in raw balsa before covering.  Dings in polyspan respond to heat as well, as does MonoKote.  Plan "B" is a well-placed decal over the Boo Boo.

Ken

There is no "under" under the ding -- it's over an open bay.
Title: Re: Dents in silkspan/dope
Post by: Ken Culbertson on May 15, 2023, 08:35:55 PM
There is no "under" under the ding -- it's over an open bay.
Plan "B"

Ken

I have racked my brain for another solution that does not end up looking worse than the ding.  I assume you have tried damp heat.  Maybe some tauting clear in the dent to soften it up followed by a blast from a MonoKote gun.  Too bad it is not pollyspan.  Anyway, Top -  Put a little "No Step" sticker over it.  Bottom - ignore it.
Title: Re: Dents in silkspan/dope
Post by: Tim Wescott on May 15, 2023, 09:08:10 PM
Plan "B"

Ken

I have racked my brain for another solution that does not end up looking worse than the ding.  I assume you have tried damp heat.  Maybe some tauting clear in the dent to soften it up followed by a blast from a MonoKote gun.  Too bad it is not pollyspan.  Anyway, Top -  Put a little "No Step" sticker over it.  Bottom - ignore it.

Moist heat was the first thing I was going to try without feedback.
Title: Re: Dents in silkspan/dope
Post by: kevin king on May 16, 2023, 12:49:46 AM
If I were you I would fill up an airbrush with 60/40 thinner/clear dope and fill the dents with clear, let dry, sand and then polish.
Title: Re: Dents in silkspan/dope
Post by: Ken Culbertson on May 16, 2023, 06:49:21 AM
So, I put some dents into my nice doped wing.  The picture makes them look better than they really are.  This is silkspan over an open bay, painted with Sig & Certified butyrate dope, bottom to top.

Is there a way to take the dents out?

(https://stunthanger.com/smf/scale-models/ercoupe-build-(slow)/?action=dlattach;attach=343224;image)
Tim - Overall where is this.  The picture leads you to believe it is at the flap joint on the outboard bottom.  And, a little off subject, what is the screw for.  I am always fascinated by innovative ways to adjust flaps.

Ken
Title: Re: Dents in silkspan/dope
Post by: Tim Wescott on May 16, 2023, 08:15:46 AM
Tim - Overall where is this.  The picture leads you to believe it is at the flap joint on the outboard bottom.  And, a little off subject, what is the screw for.  I am always fascinated by innovative ways to adjust flaps.

Ken

That's a radio hatch on a scale plane whose throttle is run with a 2.4GHz radio.

(https://stunthanger.com/smf/scale-models/ercoupe-build-(slow)/?action=dlattach;attach=300331;image)

Title: Re: Dents in silkspan/dope
Post by: Miotch on May 18, 2023, 09:04:27 AM
I have one in the side of my current build where my son picked it up over an open bay.  I've decided to live with it or put a sticker over it.  Whenever I try to fix a minor problem, I almost always create a major problem.
Title: Re: Dents in silkspan/dope
Post by: Ken Culbertson on May 18, 2023, 11:00:00 AM
 

Whenever I try to fix a minor problem, I almost always create a major problem.
Words that should be on a plaque over every workbench!  y1

Ken
Title: Re: Dents in silkspan/dope
Post by: Dave_Trible on July 25, 2023, 01:22:54 PM
Very late reply...just brush or blow on a coat of clear dope-will shrink right up.

Dave
Title: Re: Dents in silkspan/dope
Post by: Miotch on July 26, 2023, 08:52:39 AM
I looked the other day and the one I had on the fuselage of my plane finally just pulled itself smooth.  Nature can fix almost anything better than I can.
Title: Re: Dents in silkspan/dope
Post by: Dave_Trible on July 26, 2023, 12:52:27 PM
Dope shrinks until it's too brittle to do anything but crumble-sometime that's for years.  A little heat application,  perhaps just setting the airplane in the sun or a hot car for a few hours will pull out many dents and wrinkles.  When it becomes too dry to shrink much an application of a little fresh dope will reinvigorate the old dope some and make it shrink more.  You can also give new life to old covering the same way.  A coat of well-retarded and thinned clear will soften the finish and give it another life in most cases.

Dave
Title: Re: Dents in silkspan/dope
Post by: Howard Rush on July 26, 2023, 01:35:20 PM
I’d try in order:
1. A brief touch with a Mono Kote iron
2. A dab of tautening dope
3. A glob or two of dope with zinc srearate
4. Spot putty