Powdercoating Prep?

[Sonreir]

OK ladies and gents...

What kind of prep is necessary for powder coating?

My goal is to keep the flaking and chipping to a minimum when putting all the hardware back on. Is this best achieved by masking off the necessary parts prior to coating or is it better to tap and thread afterwards? If the former is preferable, how do I mask off the female portions of the threads to minimize chipping?

Thanks,
Matt

 

[SONICJK]

I usually plug all the holes with the old hardware (I replace most of it anyway) and then just take it out when you get the parts back. I havent had any chipping issues.

If youre doing it yourself or have a coater that cares you may be able to put the hardware in, spray the powder then take it out before curing so you have no worries of flaking and cracking.

 

[DaveMinella]

Powder coat is some pretty good stuff. I don't see why you'd have to worry about flaking or chipping. If you have it done right, it shouldn't be a problem.
If you're having in done professionally, your coater will mask everything that needs to be masked before laying on any powder.
Whenever I have work done though, especially on older bikes, I always ask him to leave the plugs out of the threaded holes. That way I can tap them again later, which ensures the threads are nice and tight. Be warned though: powder coating is not conductive, so if it's in any holes that require electrical grounding, make sure to plug them or file them out well before screwing any ground bolts into the holes.

 

[AlphaDogChoppers]

I have a shitload of silicone corks, plugs, and caps as well as high temperature tape, all from my powder supplier. Your powdercoater will have that stuff, too. You can also get an assortment of that stuff from Harbor Freight.

 

[crackerman]

Harbor Freight is ok, but I get most of my stuff from Eastwood. They have more of a selection of powdercoating stuff. You'll need a good base cleaner before you powdercoat. The part will chip or flake if it's not cleaned properly. I just have a small oven and powdercoat kit from Eastwood. Works pretty well. Bigger stuff like rims and frames I just send to my local powdercoater.

 

[AlphaDogChoppers]

I have some material from Eastwood. I get most of my stuff from Columbia Coatings. I just happened to pick up a plug and cap assortment at HF.

 

[JRK5892]

we typically will just retap all the holes for our customers, makes assembly 100% easier as media tends to get in there as well... plugs, masking, caps, dots, tape of all sizes... there is a ton out there! make sure you blast everything nicely (no moisture in your lines) outgass if needed.

 

[Sonreir]

I'm actually having the parts done by an industrial coater, but I've heard a few stories about messed up threads and chipped coatings. I just wanted to make sure I was doing all I can to ensure a good final finish.

Thanks, guys.

 

[JRK5892]

problem is you can not prep prior... if you mask things off when it goes thought their acid dip or blasting prior to prep you will loose all your plugs/masking. besides a special tape has to be used to mask and that does not hold up to blasting... your best bet is to mark what you need done and talk to the prep section

 

[o1marc]

I would not take any custom bike work to an industrial coater. They are usually hang-em and bang em outfits that will rarely put in the proper time prepping the parts correctly for long lasting durability. Using bolts in the holes works best and you can just throw then in the stripper after to clean them. The powder won't chip if the part is prepped correctly which means degreasing and then sand blasting the proper profile and making sure the whole part is fresh virgin metal to work with. The only good thing you will get from an industrial coater is a good price, but with powder coating you get what you pay for.

 

[JRK5892]

^ +1... 100% on point!