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914World.com _ 914World Garage _ DIY Piston top coating

Posted by: rfinegan May 29 2023, 04:44 PM

While I have the pistons out, I am thinking of applying a Ceracote / thermal coating to the tops of the pistons. Has any one tried this via a do it youself or are the DIY finishes not any good?

Posted by: mepstein May 29 2023, 05:50 PM

We send pistons, bearings, etc to HM Elliot. They do coatings for nascar and other Motorsports. Very reasonable pricing. They are in Mooresville NC.

Posted by: Cairo94507 May 30 2023, 07:47 AM

How about Teflon coating on the skirts?

Posted by: rfinegan May 30 2023, 08:30 AM

Yep, and thermal dispersion for the outside fins of the heads
all available for about 120 bucks from CeraKote

C-187 transfer grey thermal dispersion
V--36 PISTON COAT (Oven Cure)
C-109 MICRO SLICK DRY FILM LUBRICANT COATING (OVEN CURE)

I may also add the micro slick to the valve stems too and the piston coat to the chambers and valves

QUOTE(Cairo94507 @ May 30 2023, 09:47 AM)

How about Teflon coating on the skirts?

Posted by: Mikey914 May 30 2023, 09:45 AM

We use ceracoat for refinishing some of our steering racks. It requires baking. So for your application you may want to send them out. My biggest concern would be if the coating (which is quite durable ), comes off. It might act like sandpaper on the cylinder walls.

Mark

Posted by: VaccaRabite May 30 2023, 01:27 PM

As well as the piston tops, you can also put a ceramic thermal barrier coat in the combustion chamber. Some bus guys do this to assist the heads from overheating. Forces the heat out the exhaust, not near as much goes into the heads.

Whatever you use, and wherever you put it, you have to account for the thickness of the coating when building your engine. Coatings on the piston top and on the combustion chamber will tighten up your CR.

Zach

Posted by: technicalninja May 31 2023, 02:19 PM

The trick to get the Cera-coat to adhere is surface prep.

Best to start with new pistons, far less cleaning is involved.

The correct grit glass beads, a tiny bead blaster, running the glass beads through a fine filter.
Use the correct high heat tape (look at powder coating suppliers for this stuff).
Use brand new glass beads, do not re-use any of the beads as the first time through the beads truly are round and after they've hit something they're not.
Be careful with brand new glass beads. Get too many on the floor and you'll swear that it's as slick as ice.
I've busted my ass with glass beads before...

Use a good respirator. You are trying to avoid silicosis which is caused by powdered glass.

I've sacrificed an old range for this purpose. I wouldn't cook food in an oven that was used for Cera-coat or powder coat.

Cleanliness is godliness.

Even with new pistons I do a serious cleaning process. Alcohol scrub down, let dry, cook for 20-30 min at 300.
Bead blast, alcohol, cook again.
At this point cleaning is done, let them cool. Re-tape if you masked for bead blasting.
Normal painting with airbrush. Let dry in sun. Cook per instructions.

I then do a very fine polish of the surface with the finest steel wool/scotch-brite I can find.

I'd coat everything the fire touches and the entire exhaust port and back side of the exhaust valve. I leave the intake ports and back sides of valves un-coated.

If you don't have this equipment and a throw-away oven choosing a coating company is a wise choice.

Swain-Tech was my go-to for years, but they appear to have issues now.

The suggestions by mepstein look spot on and I will check their prices before I DIY my next set. I could find nothing negative regarding HM Elliot.

Miss any of the above steps and you will have coating problems. Most DIYs don't go to those levels right out of the box and that is why you see folks complaining about the DIY products.

Posted by: rfinegan May 31 2023, 03:09 PM

I have done several Cerakote Fire arm slides frames and revolvers, I do have a blast cabinet with new glass beads and 120 mesh Aluminum Oxide media, and Oven and shop air a air brushes touch up guns and paint guns
Cleaning and Gassing off is key. There are several coating companies available now but had good luck with CeraKote in the past

Thanks All..ill give it a try...