Hi John, I am experimenting at home, a new DIY project to keep me in the Mancave longer
Kev
Powder Coating
- Thread starter redbloke1956
- Start date
Kev
Thanks TT, I have the tape , just chose to paint that area
My powdercoater baked by cases and covers in the powder coating oven before he applied the powder. He said it removes any oil or other stuff that would affect the finish. You may have to bake your parts in an oven before applying the powder.
I do not know how long he leaves the parts in the oven, but it is while doing another job.
John Mead
I do not know how long he leaves the parts in the oven, but it is while doing another job.
John Mead
On all the powder coating I have had done they have to get the metal warm first for the powder to stick to it and partially melt. The powder is transferred electrostatically and then the metal component goes back into the oven for the powder to melt and flow. There might be other ways of doing this but this has been the procedure used every time I have had powder coating done.
Hi John, thanks for the info mate, i have tried that and the finish improved but still got the out gassing bubbles.
Do you have a pic of the cases? Are you happy with the finish?
Thanks TT, that is exactly what i have done and still have the bubbles
I have mine cases powder coated but they put one layer of primer coat first and after that the progress started for the final black coat "BASED" on silicone and than one coat of varnish for the shiny appearance. this all more than 20 years ago and still shiny.
Regards,
van Drenth JC
Hi Kev-
Here's a mixed reply to your powder coating blues, so take it for what it's worth.
I did not powder coated my cases, I rattle canned them.
At the time I had decided I did not want the extra thickness powder coating can give.
(were I doing them again, I probably would powder coat)
I did, however, powder coat all the other parts of the bike. (except the tank)
(a Vin twin must be about the only bike that every bit can be stuffed in a kitchen oven)(fork blades being the tightest fit)
Anyway, I used the same procedure for the cases as all the other cycle bits, even though they received paint instead of powder.
That procedure was to put the part (old paint previously removed chemically or sandblasted) in the oven at 200 degrees F for a minimum ten minutes.
Then remove from oven, and wiped clean with lacquer thinner.
That process was repeated till no grunge could be seen on the wipe down cloth. (this is using a clean cloth with each cleaning cycle)
This took a minimum of two cycles in the oven for all the cycle parts, with some taking five or six cleaning cycles, notably the engine cases, covers, and ufm, before proving to be clean.
This process was learned the hard way; with many off gassing failures till the necessity of getting ALL the contaminants out of the piece was understood.
As far as applying the powder, the preheat used for cleaning also proved helpful for powder flow out, and a strong preheat is mandatory for the thinner pieces like chain guard or headlight, otherwise orange peel is a certainty.
Heavy castings (like steering stem and engine mounts) can get away without preheat, but all parts flow better for being hot while the powder is applied.
By the way, after running out of the special powder coat masking tape, I found regular masking tape worked just fine, it simply shriveled up while baking in the oven; which was fine, as it had provided the needed protection during powder application and is a heck of a lot cheaper.
Also used the same procedure for rattle can application.
The part to be painted hot out of the oven, rattle cans waiting in kitchen sink full of tap water as hot as could be made.
The paint vehicle evaporated almost on contact with the part; so each case half took well more than a full rattle can before the paint flashed and started to flow out.
Then back in the oven for twenty minutes, followed by oven cool down.
Waited a couple of weeks before polishing out to 2000 grit wet/dry.
Best-
George
Here's a mixed reply to your powder coating blues, so take it for what it's worth.
I did not powder coated my cases, I rattle canned them.
At the time I had decided I did not want the extra thickness powder coating can give.
(were I doing them again, I probably would powder coat)
I did, however, powder coat all the other parts of the bike. (except the tank)
(a Vin twin must be about the only bike that every bit can be stuffed in a kitchen oven)(fork blades being the tightest fit)
Anyway, I used the same procedure for the cases as all the other cycle bits, even though they received paint instead of powder.
That procedure was to put the part (old paint previously removed chemically or sandblasted) in the oven at 200 degrees F for a minimum ten minutes.
Then remove from oven, and wiped clean with lacquer thinner.
That process was repeated till no grunge could be seen on the wipe down cloth. (this is using a clean cloth with each cleaning cycle)
This took a minimum of two cycles in the oven for all the cycle parts, with some taking five or six cleaning cycles, notably the engine cases, covers, and ufm, before proving to be clean.
This process was learned the hard way; with many off gassing failures till the necessity of getting ALL the contaminants out of the piece was understood.
As far as applying the powder, the preheat used for cleaning also proved helpful for powder flow out, and a strong preheat is mandatory for the thinner pieces like chain guard or headlight, otherwise orange peel is a certainty.
Heavy castings (like steering stem and engine mounts) can get away without preheat, but all parts flow better for being hot while the powder is applied.
By the way, after running out of the special powder coat masking tape, I found regular masking tape worked just fine, it simply shriveled up while baking in the oven; which was fine, as it had provided the needed protection during powder application and is a heck of a lot cheaper.
Also used the same procedure for rattle can application.
The part to be painted hot out of the oven, rattle cans waiting in kitchen sink full of tap water as hot as could be made.
The paint vehicle evaporated almost on contact with the part; so each case half took well more than a full rattle can before the paint flashed and started to flow out.
Then back in the oven for twenty minutes, followed by oven cool down.
Waited a couple of weeks before polishing out to 2000 grit wet/dry.
Best-
George
Hi George, Thanks for the vital info mate, much appreciated, I have been flying by the seat of my pants for a few months now.
Do you know if the Powder coat was Thermoset or Thermoplastic? I have used both but ended up using the Thermoset because it fluidised at a lower temperature, about 160C compared to 205C for the Thermoplastic, although it can't be re-fluidised like the Thermoplastic.
Another advantage of the Thermoset is that I ended up re-doing the coating about 6 times (before I got your welcomed advice) and finally I got a reasonable finish, after which I discovered through trial and error, that with a GREAT deal of effort and time/patience you CAN polish Thermoset coatings.
To get rid of the horrible orange peel I sanded with wet and dry paper 120 grit then 400, 800, 1200, 2000 followed by a special 12,000 I have hidden away and got a better but not shiny finish so then went onto very fine alloy polish, Clear Coat polish then a couple of hours with a super fine wax and it came up pretty good.
I am about to start on restoration of a '52 AJS 18s and all the tin ware requires painting so your input on preheating the steel will be put to the test.