Steel parts finishing

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

Joined
Jan 3, 2014
Messages
6,034
Location
Wisconsin
Hi guys. Question.

I’m undecided on what finishing system to use for the Baby Ace but I do need to prime and paint some steel parts coming up fairly soon. I like Stewarts and Airtech system but that could also change.

I want gloss black as my fuselage color.


Given that I’m still undecided on the ultimate system I’m going to use I should be able to use automotive 2 part epoxy type paint products available from my local automotive paint distributor right? I have PPG Omni products on a shelf right now from my last motorcycle project in gloss black and I’d like to be able to use it. It’s acrylic enamel if I recall but it’s a catalyzed 2 part finish.

From what I gather none of the systems have any compatibility issues with automotive paint on steel.

If I’m wrong I’d like someone to correct my assumption and I can just pick a system and stick to it and order the epoxy they supply. It just seems unnecessary because I have $300 worth of product on hand.

Thanks.
 
Last edited:

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
17,925
Location
Memphis, TN
Personally I would paint everything with either the Polyfiber or Ceconite steel tube primer. It’s really a paint primer. It’s not really a good description of what it is. Same product, different color. There are other versions used in industry with other colors. You can paint over it, but where you have fabric attached, you don’t want the glue holding onto a second paint. You want it anchored to the first. If you use automotive paint and end up using a glue like Polyfiber/Ceconite, it will melt it. Automotive epoxy paint and primer is not the same.
 
Joined
Jan 3, 2014
Messages
6,034
Location
Wisconsin
I want my fuselage and all steel parts to be gloss black. If I haven’t picked a system what the most logical step?

I’ve recovered a Taylorcraft with poly fiber and although it was certainly a very easy system the finish on metal parts was not something I will ever do again.
 

wsimpso1

Super Moderator
Staff member
Joined
Oct 18, 2003
Messages
9,457
Location
Saline Michigan
I like Stewart System too.

Many folks tell us to stick to one system from bottom to top so that you know the material on the tubes will stick and the glues and other paints will all work with it. Once you start mixing, you might be OK, you might not.

My perspective? There are only two ways I would work with mixed systems:
  • If someone I trusted had done the exact mix of primers and paints and fabric systems with good results every time. I would still be skeptical...
  • Now, if you have three years until you need to use the stuff, and you know which combo you are intending to use, then you can experiment and test. Prime/paint some test pieces and cover some with fabric right up through finish paint and any clearcoat, and put them in a rack on your roof for three years and see how they do. Maybe three years is not long enough...
Otherwise I would pay the ransom for whichever system I select, and do it per the book. A finished fuselage is no place I would be experimenting.

Billski
 
Joined
Jan 3, 2014
Messages
6,034
Location
Wisconsin
I like Stewart System too.

Many folks tell us to stick to one system from bottom to top so that you know the material on the tubes will stick and the glues and other paints will all work with it. Once you start mixing, you might be OK, you might not.

My perspective? There are only two ways I would work with mixed systems:
  • If someone I trusted had done the exact mix of primers and paints and fabric systems with good results every time. I would still be skeptical...
  • Now, if you have three years until you need to use the stuff, and you know which combo you are intending to use, then you can experiment and test. Prime/paint some test pieces and cover some with fabric right up through finish paint and any clearcoat, and put them in a rack on your roof for three years and see how they do. Maybe three years is not long enough...
Otherwise I would pay the ransom for whichever system I select, and do it per the book. A finished fuselage is no place I would be experimenting.

Billski
There’s a lot of guys who powder coat fuselages, I guess that would be mixed systems too. Chemicals are pretty harsh on powder coat, always found that strange how there’s no issues with that
 

Pops

Well-Known Member
Supporting Member
Joined
Jan 1, 2013
Messages
11,479
Location
USA.
Do not powder coat. Hard and brittle and will crack and rust under the coating.

The best is Poly-Fiber epoxy primer. Far as I know it doesn't come in black. Number 2 is Dupont Variprime , also two part and I have bought it in black. Sticks as good as Poly-Fiber epoxy primer but without a top coat it will not hold up to the elements quite as good a PF primer. It's one or the other and nothing else for me.
Can buy at your local Dupont auto paint store.

Picture is my LG primed with Poly Fiber epoxy primer without a top coat that was painted in 2006. Has seen a lot of mud and water with not ever been on a paved runway over a few times. Now the green is a little darker green as you can see on the fiberglass ends on the shock strut farings.
 

Attachments

  • DSCF0013 (2).JPG
    DSCF0013 (2).JPG
    327.5 KB · Views: 0
Last edited:

Tiger Tim

Well-Known Member
Joined
Apr 26, 2013
Messages
5,055
Location
Thunder Bay
I grew up around a shop that used a two part system to coat most if not all steel airplane parts. Not sure if it’s similar to what you have on the shelf but it’s not specifically made for airplanes and has stood up to the Randolph system and decades of wear in probably fifty-ish airframes.
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
17,925
Location
Memphis, TN
The Stewart glue is great. They have their own tube paint. Again, you don’t want a paint layer being what let’s go. Certified airplanes will have strategic floorboards and trim to hid what they can’t paint.

To me it’s now one of those things that won’t be compromised. Powder coat is a lot harder. There is the right and wrong process. I looked into it and no one local did it, so I had no reason to continue to figure it out.

It’s what you paint on stuff to keep salt water off. It’s not a primer like we call it. It’s an all in one coating that can be top coated

This is the MIL Spec stuff.
 
Joined
Jan 3, 2014
Messages
6,034
Location
Wisconsin
Thanks for the replies.

I’m not powder coating, just mentioned it because people cover powder coat fuselages all the time and that doesn’t seem to be a issue as far as compatibility.

The following photos are a WACO UPF 7 done by Rare Aircraft. They use Superflight which has been around since the 1940’s. The fuselage is gloss black and that’s what I want. I do not want a primer but rather a finished product just like the photos. Maybe that’s a unreasonable request and I’m ok to be proven wrong, I have bad ideas periodically. 😂

By Rare Aircraft restores many airplanes with incredible quality and attention to detail. I’ll try to reach out to then and see if that’s also a Superflight product on the fuselages or a automotive 2 part paint like a single stage Omni.
 

Attachments

  • 7C107AC4-5395-4321-ABEB-B4824F83A001.jpeg
    7C107AC4-5395-4321-ABEB-B4824F83A001.jpeg
    268.5 KB · Views: 2
  • 8CA3F2A5-EF97-44E5-85CF-E8E4118060D2.jpeg
    8CA3F2A5-EF97-44E5-85CF-E8E4118060D2.jpeg
    211.1 KB · Views: 1
  • A85D45CD-CB19-44D6-A387-E1A5A2C56792.jpeg
    A85D45CD-CB19-44D6-A387-E1A5A2C56792.jpeg
    65.6 KB · Views: 0

Tiger Tim

Well-Known Member
Joined
Apr 26, 2013
Messages
5,055
Location
Thunder Bay
you don’t want a paint layer being what let’s go.
Fair concern but any traditional covering system on a steel tube fuselage will have wide enough tapes or enough overlap (or both) at any seam that the covering is built up into a taut, conformal bag. I don’t think I’d be too terribly worried.

If I had one of those vintage gliders where the wing fabric just sort of glues down starting around the spar I’d be much more cautious as it’s the bond to structure doing all the work there.
 

Victor Bravo

Well-Known Member
Supporting Member
Joined
Jul 30, 2014
Messages
11,367
Location
KWHP, Los Angeles CA, USA
FWIW I recommend the Stits Poy-Fiber 2 part green epoxy primer, followed by whatever Powder Coat, paint, or top coat that will survive the glue and dope.

The primer's first and most important job is protecting the steel, because the safety and longevity of your airplane depends on it. Anything else... anything... including your desire for a color... is a distant second.

Considering the fact that you are an expert welder and likely a good craftsman, and considering a Baby Ace will last a long time (your grand kids might be flying it long after you and I are gone), I would put a far higher value on protecting the steel tubes 20-50-90 years from now than anything else.

After the Stits epoxy primer, whatever color paint you put on it can be re-done, touched up, etc. years from now - but the real protection is there doing its job.
 
Last edited:

Pops

Well-Known Member
Supporting Member
Joined
Jan 1, 2013
Messages
11,479
Location
USA.
If I was doing it, I would prime it with Poly-Fiber green of white epoxy primer ( The best) and find a black top coat that will be compatible with the fabric glue used if I had to have the tubes black.

If you use the Stewart water base fabric glue you could use about any black paint for a top coat. Personally I tried the Stewart glue and don't like it. If you use Poly-tack fabric glue the black top coat that you use will have to standup to the glue's MEK base.

I don't use any top coat because the green or white of the Poly-Fiber epoxy primer is OK with me and use the Poly-Fiber's fabric glue.
 

Scottiniowa

Active Member
Joined
Nov 29, 2021
Messages
44
Location
Clarksville, Iowa
Having painted many frames, with most of the listed above products, with great results, I would be one of the first to say, most GOOD products, applied correctly work well. This "applied correctly" part is key. But most of you know that.

But, and there always seems to be a "but" I can't get out of my head the system I saw at OSH this year,

HIPEC Aircraft Coatings | High Performance Aircraft Coatings & Fabric Aircraft Coverings

But simply can't find one single person that has used it. When I asked why that would be? I was told that it simply has not been promoted ever in the USA, can that be the reason? is it popular in Canada? IS it as good as it looks? can it really be as light as they say? Feed back folks?
 
Joined
Jan 3, 2014
Messages
6,034
Location
Wisconsin
Correct me if I’m wrong but if it were the year 1928 would the fuselage color be greenish ZC or would it be covered in silver? The original silver was aluminum mixed in the dope to prevent UV from destroying underneath it right? The Spirit of St Louis had a silver fuselage if I’m not mistaken.
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
17,925
Location
Memphis, TN
I also have an issue with most modern auto paints. They are environmental paints and they are much softer than paints made 20 years ago.

I do actually know what you should be able to paint the frame with, Imron. Nasty stuff; hurt a lot of people when it first came out, but it’s tough.
 

Pops

Well-Known Member
Supporting Member
Joined
Jan 1, 2013
Messages
11,479
Location
USA.
The fiberglass nosebowl of the SSSC was painted Imron red from paint left over from painting my neighbor's HD motorcycle.

I painted the fuselage of my daughter's 1947 C-140 with Dupont's base coat/clear coat version of Imron.
Always liked Imron and its easy to spray.
 
Top