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Building Tips and technical articles. => Paint and finishing => Topic started by: Paul Smith on April 26, 2016, 02:09:22 PM

Title: I want make this perfectly clear.
Post by: Paul Smith on April 26, 2016, 02:09:22 PM

On my speed and racing models I have been using HobbyPoxy to fuel proof the areas most exposed to fuel.  This worked OK except that the "clear" HobbyPoxy had a noticeably orange tint to it. I wrote this off to old stock.

In order to do a better job on future models with static points, I shot the big buck and stepped up to brand-new Klass Kote.  I tried it on a sport plane first.  The result wasn't much better than the old HobbyPoxy.

I'm still looking for a good fuel proof clear coat.

Title: Re: I want make this perfectly clear.
Post by: Randy Powell on April 26, 2016, 02:14:52 PM

Well, Klasskote is an epoxy based paint so it should be fairly fuel resistant. There is no such thing as "fuel proof", but some stuff is more resistant than other stuff.

Title: Re: I want make this perfectly clear.
Post by: Fredvon4 on April 26, 2016, 02:23:44 PM

Brodak Crystal clear dope or KBS Clear Diamond finish... Brodak semi fuel proof like most dopes but stays clear

KBS is fuel proof to 100%..... once gassed out it is impervious to just about any organic solvent

Title: Re: I want make this perfectly clear.
Post by: Mark Scarborough on April 26, 2016, 02:24:17 PM

autoomotive Clear coats, Urethane, are pretty clear and VERY fuel resistant,,

Title: Re: I want make this perfectly clear.
Post by: Avaiojet on April 26, 2016, 04:38:21 PM

Imron two part clear. A Dupont product.

Title: Re: I want make this perfectly clear.
Post by: billbyles on April 26, 2016, 07:41:27 PM

Quote from: Avaiojet on April 26, 2016, 04:38:21 PM

Imron two part clear. A Dupont product.

Du Pont no longer manufactures or sells Imron - the automotive paint line by Du Pont was sold to another manufacturer some time ago.

Title: Re: I want make this perfectly clear.
Post by: billbyles on April 26, 2016, 07:48:55 PM

All two-part epoxy clears will yellow in a fairly short time...well within a year.  Two-part polyurethanes do not yellow and are truly fuel-proof.  The polyurethanes that use a 1:1 base to catalyst ratio are totally solvent proof; the ones that use a 3 parts base to 1 part catalyst (such as Imron was as well as many others) have very slightly less solvent resistance, but the difference compared to the 1:1 ratio type is very slight.  Even Val Spar #327 using an 8:1 base to catalyst ratio is so fuel-proof that you won't have a problem with it.

Title: Re: I want make this perfectly clear.
Post by: Paul Smith on April 27, 2016, 07:02:14 AM

Thanks for the info.  Are these product thin enough to be used with an airbrush?

I heard that Imron is VERY toxic and not to be used without professional grade protection.

I'm looking for something more fuel proof than dope.

Title: Re: I want make this perfectly clear.
Post by: Avaiojet on April 27, 2016, 07:34:12 AM

Quote from: Paul Smith on April 27, 2016, 07:02:14 AM

Thanks for the info.  Are these product thin enough to be used with an airbrush?

I heard that Imron is VERY toxic and not to be used without professional grade protection.

I'm looking for something more fuel proof than dope.

Paul,

I don't believe you'll pump a two part auto clear through an airbrush with great success.

I just watched Robert put pen lines on a model that he eventually cleared in one of his many videos. All worth watching!

I believe Robert used a two part auto clear and a small detail spray gun.  Robert is always open for questions. He tells it straight and leaves nothing out.

If you have a good compressor you're almost there. Small detail spray guns are now inexpensive. Professional grade expensive equipment isn't necessary.

I sprayed two part auto clears for years using professional equipment and spray booths. Air hoods for breathing protection or a good mask.

Today I use a good mask and 2K Spray Max aerosol cans. I spray outside. 18.00 a can.

Works fine.

Photos of the auto clear results on my models are everywhere.

And yes, you can sand and polish the 2K Spray Max if you choose. I choose not to.

I'm looking forward to seeing you're B-25 completed.

Go for it!

Charles

Title: Re: I want make this perfectly clear.
Post by: Mark Scarborough on April 27, 2016, 08:26:35 AM

Quote from: Paul Smith on April 27, 2016, 07:02:14 AM

Thanks for the info.  Are these product thin enough to be used with an airbrush?

I heard that Imron is VERY toxic and not to be used without professional grade protection.

I'm looking for something more fuel proof than dope.

yes you absolutly can spray Urethanes through an airbrush, it may take a bit more reducer, a few more coats but it will certainly work

Title: Re: I want make this perfectly clear.
Post by: Paul Smith on April 27, 2016, 08:32:16 AM

I'm pushing to get it done in time for The Brodak.  Since this my first BIG twin I am not going overboard on detail.  I designed and built a successful 1/2A twin, but this will be my biggest and heaviest model ever.

It will just have USAF roundels and three black texts on both sides.  The main goal is to fly before May.

If all goes well I can doll it up next winter.

It weighed 5.5 pounds pre-paint.  That figure lacks final assembly glue, paint, and threaded fasteners.

Title: Re: I want make this perfectly clear.
Post by: Avaiojet on April 27, 2016, 10:45:45 AM

Paul,

I just took a look at the Brodak kit of the B-25. Interesting comments.

"Bill Avery took 1st. place Profile Scale at the Brodak 2013 Contest. Bill also took 1st. place at the 2013 Nats Profile Scale and also the High Static Award!."

Looks like you're building a first class winner!

Charles

Title: Re: I want make this perfectly clear.
Post by: Paul Smith on April 27, 2016, 11:04:26 AM

It's nice kit.  Actually quite a good deal for the price.  It involves a lot of block-sanding, which drove me to buy a belt sander, which I should have bought long ago.  The sander was almost a big of an assembly job as the plane, but it works.

Avery & Mason have a big fleet of multi-engine models that look and fly well.

More power.
More tools.
More power tools.

Tim Allen, Home Improvements

A local Detroit hero

Title: Re: I want make this perfectly clear.
Post by: billbyles on April 28, 2016, 12:26:26 PM

Quote from: Paul Smith on April 27, 2016, 07:02:14 AM

Thanks for the info.  Are these product thin enough to be used with an airbrush?

I heard that Imron is VERY toxic and not to be used without professional grade protection.

I'm looking for something more fuel proof than dope.

Hi Paul,

Imron is no more toxic than any other polyurethane using catalysts with cyanoacrylate esters as the primary component.  I spray projects the size of our models using a carbon filter mask with prefilters, available at automotive paint supply stores, Home Depot, etc. along with adequate ventilation.

As Mark noted, you can spray polyurethanes with an airbrush using more thinner than you would use for a full-size spray gun.

Title: Re: I want make this perfectly clear.
Post by: Paul Smith on April 29, 2016, 12:59:42 PM

I found a brick & mortar source of KBS Crystal Clear in the area.  I will give it a try.

Title: Re: I want make this perfectly clear.
Post by: Brent Williams on April 29, 2016, 05:56:21 PM

Quote from: Paul Smith on April 29, 2016, 12:59:42 PM

I found a brick & mortar source of KBS Crystal Clear in the area.  I will give it a try.

I hope your experience with KBS is better than mine.  I brushed the KBS on over nicely cured dope, let it dry for weeks and the instant that fuel touched it, it wrinkled and now looks awful.  Expensive little can of misery.  Ruined a nice little plane.

Title: Re: I want make this perfectly clear.
Post by: Paul Smith on April 29, 2016, 06:45:00 PM

Thanks for the warning about KBS.  I will rethink my plan.

I thought brand-new cans of Klass Kote was the answer.  It wasn't.  There are no static points in this event, so a least the Klass Kote will keep the paint on the plane.  But I was hoping for better.

Title: Re: I want make this perfectly clear.
Post by: Brent Williams on April 29, 2016, 09:55:37 PM

Omni MC270 auto clear has been used around these parts to achieve very nice results by Gordan Delaney and Roger Kramar.  
It's on Gordan's awesome Apteryx which is a concours winning plane among some seriously nice competition. (http://flyinglines.org/reg.12.fl.delaneyplane.jpg)

Title: Re: I want make this perfectly clear.
Post by: Avaiojet on April 30, 2016, 05:46:46 AM

Paul,

What clear, if any, did you apply to your outstanding Blue Angel carrier model.

Title: Re: I want make this perfectly clear.
Post by: Paul Smith on April 30, 2016, 08:13:44 AM

I used brushed-on Hobby Poxy.   It had a bit of a tint to it that changed the colors of the yellow and blue, but scale accuracy was not an issue.  I was willing to accept the tint in the epoxy in events including Carrier, Speed and Racing.  Even in Stunt I epoxied the engine area and tolerated a bit of yellowing,

I wanted to do better on my B-25 and put my faith in Klass Kote.  But my test model didn't fair much better than Hobby Poxy.

I'm planning to browse a paint store today.

Early on I bought a "small" spray gun to use for clear coating with dope.  But it's still too big for my models it wastes too much dope and there's too much overspray.  I settled on spending more time to clear coat with my air brush.  It takes a while longer but the overspray and waste is minimized.

Title: Re: I want make this perfectly clear.
Post by: Walter Hicks on April 30, 2016, 01:49:19 PM

Paul I use two part auto clear all the time sprayed only with an airbrush. It works very well and forces you to thin it and keep the paint amount down.

(http://i82.photobucket.com/albums/j262/kickercoach12/20160204_131042.jpg) (http://s82.photobucket.com/user/kickercoach12/media/20160204_131042.jpg.html)

Title: Re: I want make this perfectly clear.
Post by: Jim Roselle on May 09, 2016, 07:49:01 AM

Quote from: Brent Williams on April 29, 2016, 05:56:21 PM

I hope your experience with KBS is better than mine.  I brushed the KBS on over nicely cured dope, let it dry for weeks and the instant that fuel touched it, it wrinkled and now looks awful.  Expensive little can of misery.  Ruined a nice little plane.

I had the same experience. I have a model that was coated with kbs clear well over a year ago and 35% still chews it up to this day.

Jim

Title: Re: I want make this perfectly clear.
Post by: EddyR on May 09, 2016, 11:08:32 AM

I was one of the first on here to use KBS. I had used it for several years on repainted bicycle frames and it works perfect for that use. If used on a new plane it seems to work well and looks like glass finish. I used it on several older planes that were cleaned as best as possible. They looked great, better than new for six months and then any place exhaust had gotten the plane before it was painted with KBS began to craze. The nose,fillets,flap to trailing edge joint. Now those planes are sitting all stripped down and waiting to be recovered. For a one season plane KBS would be fine. The two part in the spray can is better. Here is my ten year old Falcon after I put KBS brushed on it.

Title: Re: I want make this perfectly clear.
Post by: Steve Conn on November 17, 2016, 11:37:21 AM

Quote from: Mark Scarborough on April 26, 2016, 02:24:17 PM

autoomotive Clear coats, Urethane, are pretty clear and VERY fuel resistant,,

Mark:   How are you applying the automotive clear coat?   Spray or brush?

Title: Re: I want make this perfectly clear.
Post by: Mark Scarborough on November 17, 2016, 11:45:37 AM

Quote from: Steve Conn on November 17, 2016, 11:37:21 AM

Mark:   How are you applying the automotive clear coat?   Spray or brush?

with spray gun, technically I spray my color coats with an Iwata detail gun, and my clear with a SATA Minijet.

I use a brush to build up dope and sand, then spray from that point on