MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Powder coating

A quick tip. I just tried my powder coater on a steel valve cover. I REALLY should have used it sooner (been on my shelf for 3 months) and I would have coated all the sheet metal bits under my hood instead of using paint. It does a great a job and it is easy and quick to use. Much faster than painting. Curing done in wife's oven with no fumes/mess. Bought it at harbor Freight for $59.00 on sale.
David

I may have to check into this thanks.
The G

As far as I can tell, the downsides to powder coating are:

1. The coating must be done on bare metal, so if you have to do ANY filling, you are out of luck. I don't know if the powder coat will bond to leading, so that might be an alternative.

2. Whatever piece you powder coat must be small enough to fit into your curer. If you are doing this at home, this means the oven. I've seen home kits that say you can cure the coating with heat lamps. I'm skeptical of that.

3. Limited color selection. I want to powder coat the valve cover for my TF-1500, but I can't find something to match the light greenish tone that most authorities seem to think is original. I don't know if any suppliers offer the ability to custom mix colors for powder coating, but I've never seen it.

4. You have to be able to heat whatever you are powder coating to the curing temperature. Which means complete disassembly for many components, like generators, to paint them.

IMO, powder coating is good stuff, but it's limited in applicability. Great idea for valve covers and other under hood stuff, if you can find the right color.
Mark B.

Pardon the ignorance here....
I like the looks of powder coating but will it not simply melt away from parts which receive even marginal heat from the engine,(Valve covers, thermostat pipes etc)? Or is it as heat resistive as high temp paint? Had some wheels bead blasted and powder coated with great satisfaction once, but was skeptical concerning the durability on parts that get hot.
TDHoward

TDHoward,
Your question got me curious, as I have been following this thread with interest. As I know nothing about powder coating, I did a little web searching. Here's a snippet from some info I found at:
http://www.spraytechsys.com

=======================================
Types of Powder Coatings

Powder is basically dry paint consisting of 4 or 5 components:

1. Resin
2. Crosslinker (not used in Thermo plastic powders)
3. Pigments
4. Flow Aids
5. Degassing Solvent (Solid)

Two basic types of powders:
Thermoset Powders –Curing or crosslinking takes place so that once cured, the coating will not remelt.
The majority of powder coatings today are thermosetting type powder.
Typical Thermosetting type powders are:

o Epoxies
o Acrylics
o Most polyesters

Thermoplastic Powders – Do not crosslink and can remelt after curing when exposed to sufficient heat.
Typical Thermoplastic powders are:

o Vinyls
o Nylons
o Fluorocarbons

=======================================

So it sounds like with the right powder, valve covers etc might be ideal candidates. I'm thinking air cleaner housings, pedal box covers, heater boxes....
Rob Edwards

Mark B.

Here's a place that I've found that has a pretty large color selection for powder coating. They're located in Michigan.

http://www.exoticcoatings.com/colors.htm

Take a look, they might have the green that matches.

Mark

Mark Wasunyk

Thanks, Mark W.! That's cool. I kind of have a hard time with subtle color differences, but I'll have a few people look at that page and see if they can agree on a color that matches.

MB
Mark B.

While powdercoating is a nice finish a lot of care must be taken to ensure a long life. Since the paint is melted on it it an 'almost' impervious finish which is good and bad. If there is any rust or moisture trapped on the piece the paint will lift rather quickly. I recommend heating the part to evaporate any moisure prior to painting. According to Mil Specs, the piece should be sand/bead blasted prior to application. Better yet is to have the part zinc coated first. Moreover, powder coating is susceptible to brake fluid and antifreeze. This I know from personal experience. I have found POR 15 to be as good and far more durable. And your wife will still love you for not ruining her oven :)
datsooonmike

A few points not already covered on PC.

1) A great alternative to chrome plating since there is no risk of hydrogen embrittlement.

2) Like any other finish...cut corners in the preparation and it will show in the final product.

3) PC is also available in a "clear" so polished alloy valve covers etc can look the same but be protected from "powdering" caused by oxidation.

4) There is also a PC "wrinkle finish" in black suitable for restoring the original look to metal dash boards. NOTE: This is hard to find outside the USA for some obscure reason.

5) PC is somewhat flexible and can be reapplied to fill chips, scratches and so on. Some places are not willing to do it because it requires a very competent operator to get a smooth finish from the fusion of the old and new materials.

6) Like everything else "you pays yer money and you takes yer choice" as the old saying goes. In other words do not condemn the process because of one incompetent operation or operator.

Cheers, Pete.
Peter Thomas

Hmm. Perhaps the clear on the windscreen frame?
Rob Edwards

very interesting information. Thanks for the links.

I would wonder if filling with lead or with brazing (more conductive, but more difficult to shape and finish) would work for filling dings and dents in sheetmetal before Powder coating? And, as mentioned in another thread on refurbishing a front cross member, does powder coating lend itself to interior spaces?? I would think it could, but what is the real world experience in such cases???
bobmunch

Several of my friends and I have been powdercoating for quite some time. My latest job is the complete front suspension (mirror black)of my 77 B roadster and a 1970 Rover 3.5 liter aluminum v8 block and heads (clearcoat). We've done everything from tools to drive shafts, engines, carburetor bodies, intake manifolds, bumper brackets, alternator housings, pulleys, brake drums and calipers, master cylinders, motorcycle cylinder barrels, wheel rims and the list goes on. We use a standard oven with a custom built double metal wall insulated box that fits on the oven door when it is in the open postion. This doubles the useable heating space. A brace for the open door allows us to do heavy items such as engine blocks.
We use the coatings and system from Eastwood. They have a very wide selection of colours and specialty coatings and very reasonably priced in quanity (we usually combine and buy in 5 pound lots).
The secret to a good job is a clean grease free surface. I always degrease, sandblast or bead blast, then wash with clean lacquer thinner to remove any trace of remaining grease before coating. I recently did the valve covers for my Rover v8 in wrinkle powder coat. With the raised fins buffed shiny after the powder coat, they look terrific.
The powder does go into interior and "deadend" spaces quite well due to the electrostatic charge drawing the very fine powder, however there are limitations due to distance, corners and other obstacles.
Phil

In additon to powder coating, there are a number of industrial finishes which have application to automotive problems. I have been using a product called Gun Kote, originally developed for application to tank cannon, for several years now. It is available in shiny black, matte black and gray, perhaps other colors. It is a spray on moly finish that is baked on. It is resistant to most solvents, including brake fluid. Parts coated must be baked for an hour at 300 degrees. For small parts (such as a brake master cylinder) an old toaster oven may be used. For larger parts, I use an old kitchen oven. The black Gun Kote seems to be holding up very well on rear brake drums--much better than the paint I used on another set. As has been pointed out, all of these products form a barrier between the metal and the atmosphere. So, a clean surface is essential. Gun Kote can be applied over solder, lead, brazing, etc. as long as the melting point of the item is above the curing temperature. Les
Les Bengtson

Bobmunch,
Yes PC can be used over different metals but as it needs to be baked in an over to obtain the fusion of the raw powder into a coating it would be ise to ensure the differeence in temperatures between the filler and the bake oven are enough to avoid melting the filler.

PC can be used in internal applications as well but I would opt for a fill and slosh method using POR15 or similar to ensure a complete coverage.
That does work well from personal experience.

Cheers, Pete.
Peter Thomas

This thread was discussed between 12/12/2002 and 15/12/2002

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.