How To Use Powder Coat Repair

Columnist, Products Finishing mag

Question: I've been told that a pulverization coated part cannot be "touched-up." I have some patio piece of furniture that I had pulverisation coated and the pulverization coating store that did the work for me stripped the threads in holes used to rack the part. I tin can fix the threads by welding up the pigsty and re-taping the threads. The shop states the whole piece will demand to be redone and they cannot address merely the pocket-sized surface area affected past the repair. Is this accurate? Is it true that pulverisation blanket cannot be touched upward?

Answer: You cannot touch upward a small area of a pulverisation coated part with powder. It will leave a visible departing line betwixt the original coated area and the touch on-up area that is dry out and rough looking. You may want to consider touching up with a liquid paint. Typical aerosol paints volition not have the same performance as the powder but they can cover upwards an area cosmetically and yous should be able to match the powder color pretty closely if not perfectly. If the area is very pocket-sized this may be acceptable, but you need to know that the aerosol is not as tough as the pulverization and it may rust or discolor sooner than you want.

In some cases, a function is touched up with a color matched, two-component polyurethane liquid paint by brush or spray. The departing line may be visible but it is non very obvious if done properly. This will give y'all better performance. It may not wear or discolor at the same rate every bit the powder, and so color match may be more than noticeable over time. If y'all are concerned well-nigh the performance and want perfect appearance, yous volition demand to recoat the whole function subsequently you practice the repair. The repair area needs to exist cleaned (probably sanded) and so the whole function volition receive a 2nd coat. Hopefully, the powder coater volition accept responsibility for ruining the threads and do this at no charge. The extra layer of powder will exist a benefit and will provide better habiliment over time. One caution: they volition need to confirm that the two layers volition have good inner-coat adhesion; they tin can practice this by testing a console to ostend expert adhesion.

big-area touch-Up?

Question: I have a quick question about touching upwardly of pulverisation pigment. What would be the possibility of touching upward a big expanse, let's say a 12 × 12-inch spot, and curing with a controlled heat source that would concentrate the heat in such a way that it would allow baking of new powder without damaging the outer layer powder surrounding the 12-inch area? H.B.

Answer: Unfortunately, yous will not be able to use powder to do an isolated spot of touch-up on a larger surface. When you utilize powder over powder y'all must glaze the entire part 100%. The affect-upward area will show a very crude and grainy line between the expanse you glaze and the original coat.

It would also exist very difficult to apply a heat source selectively to a small area and achieve proper cure, and you may take a chance discoloration of the original coat.

If you must affect-up an expanse equally large as 12 × 12 inches without rerunning the entire role, you could endeavour a liquid touch-up pigment. Powder tin can be color matched with an acrylic spray. These droplets spray cans are practiced for pocket-sized, cosmetic touch-ups but not too good for larger patches— performance of the acrylic will not exist as practiced as the pulverisation, so it may fade or interruption downwardly in a relatively short period of fourth dimension.

You tin can too utilise a 2-component urethane liquid. This will give you amend performance, simply it will still be hard to avoid leaving a noticeable parting line. The all-time thing to exercise from a performance and appearance standpoint is to simply recoat the entire part. Bicycle it back through the system and apply a complete 2d coat.

If y'all do recoat the role, be aware that the insulated surface will be harder to cover due to electric resistance. Apply low amperage (<20 µA), increment pulverization menses slightly, and continue the gun a fiddling further from the target than normal. Be certain to get consummate coverage; any missed areas will look grainy and wearisome.

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Source: https://www.pfonline.com/articles/powder-coating-clinic-touch-up-options-for-powder-coated-parts

Posted by: albertsonsompark.blogspot.com

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