Topic: Powder coating, outgassing

[scrambler]

Hey Guys,

I got my parts back from a local powder coating company but I`m not happy with the results. I`ll take them back, or I`ll ask a partial refund because they cost a lot, but first I just wanted to ask around here if you guys had similar issues. I know these old aluminum parts are porous and can cause outgassing, but there has to be a solution for this, or if not, they wouldn`t have taken the job in the first place. Somewhere I`ve read that if you keep the parts in the oven for a few hours before doing the coating all the air will come out and the rest of the procedure works out just fine.

Here`s a pic of the unicorn "top tree", most of the aluminum parts are full of bubbles like this:

[HondaMan]

That's ugly!

[Dimitri13]

Sorry that happened to you.

I'm unsure how to make it not do that but when I had my engine pieces powdercoated I had no outgassing or bubbles in the finish. I don't know what procedure was used but everything was media blasted beforehand.

[PeWe]

The bubbles are not visible when the part is mounted on rhe bike? Gauges and bar clamp(s) cover some too.

[scrambler]

Yeah, but this is not the only part. The caliper looks the same for instance, and the handlebar switches too..

[pjlogue]

I would say it was due to poor prep of the part rather than out gassing.  (True "out gassing" of cast Aluminum is usually from newer cast pieces. 40 year old parts usually aren't a problem)  Any contamination on the part will cause that bubbling.  To fix that you should have it sand blasted and then the part should be washed in a detergent hot water solution, then rinsed in distilled water, then final wipe down with Acetone.  The part should then be heated to drive off any moisture/acetone that might be in small pores. 

I have done a good bit of PC on my bike parts over the years and early on I would get that bubbling once in a while.  Every time it was because I didn't do a good enough job in either prepping the part, or making sure the solvent was driven off by preheating.  The rougher the surface the more important it is to preheat and drive off the solvent.

The guy that did the PC may also have used contaminated or very old powder.  Reputable PC places will usually sandblast any parts they intend to PC regardless of the condition of the part you bring them, even if you sandblasted it yourself.  It is their insurance that the part you get back does not look like the piece you have. 

As with a professional paint job, PC is 99% in the preparation of the part.

-P. 

[XC204]

I agree with pjlogue prep prep prep I do powder coating in my garage with a Columbia Coatings gun and home built oven and controls that I made. Steel parts I clean, sand blast wipe down with alcohol  burn off any fibers from wipe down with a torch then coat and bake.Cast aluminum I usually add prebake for outgassing , outgass free primer (powder coating)  then hot flock the color coat and bake. I've had had a few that I skipped the OGF primer and they bubbled. Here are some of my CB500-K engine parts. The brown parts are steel except the valve cover I did them as a batch and skipped the OGF primer the valve cover bubbled! As a side note the new  strippers without MEK do not want to do Powder coated parts.

[XC204]

Oops the OGF primer was from powder by the pound the other colors are from Columbia Coatings

[MauiK3]

POR 15 works well, cheaper to.

[Stev-o]

I've had triples done by by local powder guy and they have always come out looking "luscious"!
We've never discussed he had to do something special for prep other than blasting.

[scrambler]

Yeah, I think it`s just sloppy work. I should learn how to do PD myself I guess, I could save so much time and money on these things. It would`ve turned out better if I just had used a spray can for a few bucks.

[Dimitri13]

I would definitely go back to the company and ask them what they're going to do about it.

Chances are that if it's not an automotive specialty place, most of their work comes from non-automotive stuff like agriculture, furniture, fences/gates, signs etc. The local place I got a quote from did lots of lawn furniture, gates, and toolboxes.

[scrambler]

I took them back, the boss will be back on Monday, they’ll show him the parts and he’ll call me. But the guy at the front desk said it’s the material and related porosity and subsequent outgassing.

[Dimitri13]

I'm pretty sure our bikes are not the only things in the world made of cast aluminum...

[scrambler]

Exactly. If they refuse to redo it I’ll ask for refund, they should’ve told me they wouldn’t be able to make it in the first place. This is just unacceptable.

[Stev-o]

I love fresh powder!




Had these done a couple years back from my powder guy.  He's just "a guy" and not a company, so I only deal with him.

[evinrude7]

I love fresh powder!




Had these done a couple years back from my powder guy.  He's just "a guy" and not a company, so I only deal with him.

how does the power hold up on that sprocket after use? 

[Ichiban 4]

Hey Guys,

I got my parts back from a local powder coating company but I`m not happy with the results. I`ll take them back, or I`ll ask a partial refund because they cost a lot, but first I just wanted to ask around here if you guys had similar issues. I know these old aluminum parts are porous and can cause outgassing, but there has to be a solution for this, or if not, they wouldn`t have taken the job in the first place. Somewhere I`ve read that if you keep the parts in the oven for a few hours before doing the coating all the air will come out and the rest of the procedure works out just fine.

Here`s a pic of the unicorn "top tree", most of the aluminum parts are full of bubbles like this:

_____________________________________________________________________________________________________
I've only had a little powder coating done over the years (have done a lot of regular paint tho)..and aluminum parts have been no problem..as long as the parts were cleaned thoroughly before painting/powder coating.
That bubbling looks like bad preparation to me.  And the excuse from powder-coater that it was due to "outguessing" sounds like buck-passing to me. If the part(s) were gradually heated during the coating process..and the parts adequately cleaned beforehand..that shouldn't have happened..I'm thinking. [BTW: I've powder coated brake parts..master cylinders..et al..and never had that bubbling problem]
I try to thank/praise for work well done.  I also don't accept shoddy work with lame excuses about why it didn't turn-out well.  If were me..I'd tell them to do it over..and/or refund my money.  Then take it to someone who can do the work properly.
Best of luck..
Al/Ichi

[jgger]

Take the parts to another shop and get their opinion an what is going on. Plus a price to fix it. That way you are loaded with professional information and not internet guesses.

[Stev-o]

I love fresh powder!




Had these done a couple years back from my powder guy.  He's just "a guy" and not a company, so I only deal with him.

how does the powder hold up on that sprocket after use?

Has help up remarkedly well

[greenjeans]

Just from that pic, they layed it on way too thick.  Look at good pc from places that know what they are doing and its much thinner.  Much thinner.
Alot of these guys are heavy-handed.

[754]

 I  would be leery of heating up them unicorns, sorta fragile..
 I hope they blast the mess off , because heatingit more would be scary...

[scottly]

Just from that pic, they layed it on way too thick.  Look at good pc from places that know what they are doing and its much thinner.  Much thinner.
Alot of these guys are heavy-handed.

I agree, it looks way too thick, and was possibly heated too much.