SFC frame coating repair

F

Franco58

Junior member
Location
New Brunswick, Canada
Hi folks,

During disassembly of my SFC, I've noticed that the coating has been damaged at one point by a leaking battery. It looks like the previous owner attempted to repair the damage with paint, but it's a marginal job. I also noticed that there is significant surface rust around the pivot area if the stand.

So...

How was the frame coated in the first place? Was it dipped or spray-coated?

What would be the best approach to refinish the frame? What product would be the best match  to the original?

Does anyone here have any experience with this?

Thanks in advance!

Frank
 
This is what his first post said.

I haven't picked it up yet, but I just bought a project bike. The bike is a 1974 750 SFC and I've known about it for over 40 years.

It was bought in 1977 and has been stored, under less than ideal conditions, since 1981. The owner passed away 4 years ago and I recently bought the bike from his wife. Seized brakes, surface corrosion and a ton of dirt, but everything is there, including both exhaust systems. An internal camera inspection shows a very clean engine with the usual carbon build up.
 
The search facility on this forum ;) brought up some threads which might make useful reading. The 750SFC guru Marnix v d Schalk reckons drum braked bike frames were cadmium plated and later disc braked models zinc. You almost certainly won't get a more accurate answer than that!
https://laverdaforum.com/xf/threads/100382/
https://laverdaforum.com/xf/threads/81962/

I'd recommend trying to preserve/match the original finish and explore the option of a suitable spray paint finish to refinish the damaged area.

Also interesting to see Marnix say "the few unrestored/untouched drum brake SFCs that I saw all had a thin layer of matt silver paint to make an even finish."
 
Thanks very much for the information! I don't want to destroy the original finish, but I would like to clean and protect the frame where it's been marred, if I can. The original owner tried to protect the frame where the tank rubbed by covering the spots with duct tape. The protection was short-lived.
 
Yeah the top frame rails under the tank on mine has also rubbed bare from the tank tunnel. No clearance to put any protective cover either.
Fibreglass is very abrasive!!. Don't see it very often so don't think about it!!
 
I wrapped the top frame rails in inner tube. Did the job.

The zinc coating on the frames is not very long lasting and tarnishes by patches.
I believe the last ones were painted.

Patina.

Paul
 
Franco - I would fix the frame paint with epoxy paint airbrushed on. Level the surface with 220, then 400 and then 600 paper. You don't want any edge were paint meets bare metal. Clean with tar remover from auto parts store. Then spray. With epoxy, you don't need any primer and it will not come off with solvents. It's on for good. Unless you do the entire frame, you will get a halo from the spray around the area that you sprayed. There is no avoiding this with any paint unless you brush it on. To get rid of this, you will have to wet sand with progressively finer grits of paper down to probably about 2000 and then polish with a slightly abrasive compound.

The epoxy may be found here: Epoxy Coatings - Colors, Clears and Primers - Klass Kote
Rob
 
I found these three to be the best match.


www.maxwarehouse.com

Rust-Oleum Professional Galvanized Bright Gray Galvanizing Compound Spray 20 oz.

Rust-Oleum Professional brings you the Bright Galvanizing Compound Spray to galvanize surfaces like gutters and fences. The Rust-Oleum spray paint contains a high loading of zinc, and the Bright Galvanizing Compound allows you to match newer galvanized surfaces. It is optimal to use the...
www.maxwarehouse.com www.maxwarehouse.com
gclid=CjwKCAiA9bmABhBbEiwASb35V5CqDoSGXO9fTphICGr-23z7xv1eYVAo9Vw4oyv5D1LsBztLkIx2whoCeNkQAvD_BwE

WEICON Zinc 550 Cold Galvanizing Spray 400 mL

WEICON 11000400 Zinc 550 Cold Galvanizing Spray 400ml WEICON Zinc Spray can be used as a high-grade anti-rust primer for the coating of welded joints and drill holes as a conductive intermediate layer for spot welding and wherever metal must be protected against corrosion WEICON Zinc Spray is
www.usaindustrialsupply.com www.usaindustrialsupply.com


All very similar but for me the weicon turned out the best. I chose to match the patina as opposed to making it perfect. matches the other side pretty well. Only the left side needed to be addressed. Photo of right side is just for comparison.
 

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Admin said:
Also interesting to see Marnix say "the few unrestored/untouched drum brake SFCs that I saw all had a thin layer of matt silver paint to make an even finish."
Click to expand...
that sound very much like the way the 2-1 exhaust is. Plated and then painted. You can sort of see it in this pic.
 

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78jotadave said:
Just wondering if the frame could be nickel-plated the finish would certainly look good, what would be the drawbacks? I think Rickmans had nickel-plated frames and the ones I have seen 40+ years on look pretty good even after all those years.
Click to expand...
Bit too shiny for a SFC, if you go to the trouble of plating may as well do it with zinc which is original if I'm correct in my thinking.
Always thought it was cadmium though.
 
motoddrob said:
Bit too shiny for a SFC, if you go to the trouble of plating may as well do it with zinc which is original if I'm correct in my thinking.
Always thought it was cadmium though.
Click to expand...
Thomas Aus Lau on here has nickel plated his SFC. If it's done right it works (Thomas used a different system from std electroplating) - I had my SF frame done and it was a total failure. You also need to get a nice shiny finish on your base metal if you want it to look like a Rickman. I'd consider the better method, but if I ever want to weld the frame again I'd need to have it redone.
BTW, don't think my factory 2/1 ever had paint on it - could be wrong.
 
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