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Building Tips and technical articles. => Paint and finishing => Topic started by: Jim Treace on October 16, 2008, 12:17:17 PM

Title: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Jim Treace on October 16, 2008, 12:17:17 PM
I assume that my answerer is somewhere on the site, but can't find it. Can LusterKote clear be used over Sig Supercoat dope? If not, what other spray can fuel proof clear could I use over the Sig Supercoat dope?
Thanks,
Jim
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Leester on October 16, 2008, 02:02:50 PM
I'm pretty sure you can use LustreKote over dope just not dope over Lustrekote, but to be safe try a test piece. Minwax clear Poly is one you could test while your at it.
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Larrys4227 on October 16, 2008, 02:05:45 PM
While we're on the subject, what spray can clear can I use over Rustoleum? I'm concerned about yellowing ...

FlySafe!  Larry (Larrys4227)
Title: Re: Spray can fuel proof clear over Sig Super Coat dope
Post by: Jim Treace on October 17, 2008, 08:51:18 AM
I'm pretty sure you can use LustreKote over dope just not dope over Lustrekote, but to be safe try a test piece. Minwax clear Poly is one you could test while your at it.

Well, dang-it! All of this is going to have to wait a bit. I really goofed up. I wanted a practice plane so I took a Tutor II ARF, stripped all the covering, installed Morris controls, beefed up the engine mount and covered in Polyspan and sealed it with Sig Super coat. Covering looked great. To keep it light I used dyed dope, but I used Sig Super Coat dope as the substrate for the dye. A few hours later and the Super Coat shrank so much that it has torn the polyspan. Gee, what a mess. And it was looking so nice. Anyway, I am in the process of applying silk span patches to all the tears. This will take some time and I probably won't get the effect of dyed covering that I wanted.
Is patching the best route to take or do I strip all the polyspan off and start over? Not even sure this can be done.
Darn!
Jim

Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Jim Oliver on October 17, 2008, 12:20:17 PM
Jim,
I have only used polyspan once but can't imagine why it would rupture/tear as in your pic.........
did you run the grain spanwise?

On my application, I sanded into the polyspan------what a mess!!  Finally used acetone and lots of paper towels to remove the covering, down to the wood.

Cheers,
Jim
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: john e. holliday on October 18, 2008, 08:14:41 AM
I too am surprised that the polyspan has split the directions shown in the pictures.  I have several planes that are covered with polyspan.   On the Spitfire I held the heat gun in one spot too long and had to patch the area.  Too me it also looks like not enough clear dope was put on befor color was added.  Have fun,  DOC Holliday
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Jim Treace on October 18, 2008, 09:26:44 AM
I believe my problem was self induced! I too have used polyspan on many of my planes with absolutely no problems with Brodak dope for color coat and Sig lite for clear coat. But in this case, I used Sig Supercoat to attach, let dry, then a little heat to shrink out the wrinkles and tighten up. Then three coats of Sig Supercoat. Let dry. Really tightened up and looked great. Finally (think this was my problem), mixed color dye with Sig Supercoat and painted it on (didn't have access to my spray gun). It took three coats to cover and it had to be in heavier amounts than a spray gun. I believe that I just over applied taunting dope to an already pretty tight covering job.  It looks pretty awful!  And would be too heavy if I over cover in silk span and then re-color. I am going to take it all off and start again. Off to hardware store for acetone and paper towels. Yuk!
Jim
ps: my wife says I spend too much time building and not enough time flying. Think she has a point here!!
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Leester on October 19, 2008, 11:03:06 AM
Might want to use the Sig Lite Coat as it is low shrink.
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Ward Van Duzer on October 19, 2008, 12:18:16 PM
We seem to have lost the thread here. I too am interested in what kind of fuel proof rattlecan clear can be used over Sig dope.

Anyone please...


Ward
Title: Re: Spray can fuel proof clear over Sig Super Coat dope
Post by: Jim Treace on October 19, 2008, 03:35:42 PM
We seem to have lost the thread here. I too am interested in what kind of fuel proof rattlecan clear can be used over Sig dope.

Anyone please...


Ward

Ward:
Before I had the tear problem in my polyspan, I was planning on using Luster Kote clear over the Sig Super Coat, as I tested it over a dried sample of my dyed Sig Super coat mixture. Did not seem to cause any problems. I have not tested Minwax clear.
Jim
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Balsa Butcher on October 27, 2008, 05:44:41 PM
I have used Lustre Coat Clear over Sig.  At first I was impressed, one quick coat, instant shine.  Adhesion problems surfaced later after the plane got a few dings.  The Lustre Coat would peel off in big sheets exposing the not-so-shiney dope underneath.  I think it is probably because of the different drying characteristics of the two paints.  I won't use it again.  I suggest a couple of coats of spray-can Sig Buterate then go fly  y1
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Jim Treace on October 29, 2008, 07:21:08 PM
I suggest a couple of coats of spray-can Sig Buterate then go fly  y1
Pete:
Thanks for the information about the LusterKote clear over Sig. My test piece looks OK, but then, it has not aged very long. So, I will not use it. Anyway, where do you find Sig Butyrate in a spray can? I can't seem to find it on Sig web page.
Jim
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Richard Grogan on October 30, 2008, 02:29:08 AM
I'm pretty sure you can use LustreKote over dope just not dope over Lustrekote, but to be safe try a test piece. Minwax clear Poly is one you could test while your at it.
Minwax Polyurethane works well, except it has no UV protectants in it and will yellow very soon. I deliberately used it on my 51 Nobler and my 2 original paint scheme'd Ringmasters(all 3 were dope finishes). It turns white wings into Diane creme! You also need to scuff-up (steel wool) the finish a little before application.It wont stick to your graphics if you don't. If you dont want patina,then don't use it!
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Balsa Butcher on October 30, 2008, 08:26:34 AM
Jim:  If  Sig clear in a spray can is not longer available - that is news to me.  I buy mine at a LHS in the Sig rack.  My understanding is that it, like Sig colors, are lite-coat even though it does not say so on the can.  I only use it as a touch up as dope bought that way is expensive but it does spray on smooth. I wish the lustre-coat adhered better because it does result in a real nice instant shine.
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Ward Van Duzer on October 30, 2008, 01:53:06 PM
Perhaps we need to try the steel wool bit BEFORE the Lustre Coat...

Anyone?


Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Balsa Butcher on October 30, 2008, 02:21:02 PM
Actually the 000 or 0000 grit steel wool that is commonly used would leave the surface too smooth for a lustre-coat top coat.  I would not prepare the surface with anything finer than 600 grit sand paper, possible even 400 to give the top coat something to "bite" on.  It may help. Other's expericenes may differ.
Title: Re: Spray can fuel proof clear over Sig SuperCoat dope
Post by: Jim Treace on November 10, 2008, 07:06:08 PM
Off to hardware store for acetone and paper towels. Yuk!
Jim

Well, I know I started this thread looking for a spray can dope/finish over Sig dope and I kind of got off the mark, but just to give an update on my Tutor II polyspan splitting problem. It was so bad and ugly that I had to strip it all off (kept wing tips). Used lots of acetone. The red fluorescent dye that I used is really messy! Once done, I used LusterKote on the sold wood and Monokote on the open bays wing & stab. It looks OK, not great, but this will be my knock around ship. Before and after photos.
I still need to clear finish the wing tips. Not sure what I'll use...maybe just go to Sig Lite Coat and call it quits! I think my original problem was using Sig Super Coat as the mixing medium for the dye. Too much tauting and it may have not helped that the dye mixed in the thinner, then in the dope, never seemed to be nice and "creamy". Kind of had micro grains and feels a little gritty. I used the red fluorescent dye pigment from Model Research Labs, Mission Viejo, CA. and followed the directions, but there must be other variables in doing this that I missed.
Jim