I also bought my fluid bed from TJ's many years ago. I have a 4" diameter bed. TJ's was clearing out the 4", said they were no longer going to sell that size, so I ended up buying every additional cup they had and they made some extra for me. Great business to deal with!
One thing that is often not mentioned in these powder coat discussions, is moisture and how it affects the process. Fine powders of any type, even food such as flour, tend to absorb moisture, even from humidity in the air. In discussions, some folks complain about coating problems, and they get many replies about heat and so forth, but it's probably that some have problems because they don't keep their powders dry. When you get powders, at least in bulk, they have a label that states that it's best to keep them sealed and dry!
I use bulk powder, bought by the pound, and I put forth a lot of effort keeping powders sealed in containers, and in my bed cups, I seal them and place silica gel packs in the cups when not in use, to aid in limiting moisture. I live in SC, and this time of year and into the late fall it can be very humid. Even a tiny bit of moisture can affect how the powders coat, and that's going to have some affect on your end result.
None of this is real critical, not life or death, but I read a lot of comments on topics like this and frankly, some of it makes me cringe because of the misinformation that is passed around. Keep the powders as dry as possible. Learn what heat is best for you, and be consistent in your process once you do figure it out. As the size of the jigs you're coating changes you may need to make some adjustments, simply due to a difference in surface area, but's not going to be extreme.
In a recent Facebook discussion, I mentioned exactly this, and posted photo's of some jigs that I had coated and I explained what I do. I specifically said, make sure the powder is fluid, and "fluffy", and I said only dip, straight in & out. That will provide an even coat, and the thinnest coat, which is what you want with most powders, and sure enough, another person commented to swish the jig around in the powder! OK, we all do things a bit differently, but that contradicts logic if the problem is getting too much powder on the jig. The longer that jig is in that powder, the more powder will get on the jig! That also applies to this moisture issue and IMO, a lot of folks do things that defeats the use of powder coat.
Again, you're coating a jig, and not curing cancer, but use a bit of sense & good judgement about it. Thin, even coats will provide the best results. The temperature for coating and curing should be close to being consistent in your process and the powder manufacturer tells you what temperature they should be cured at and the time frame to be used. Most that I use cure at 400 degree's and I get very good results at around that temp for about 20 minutes with most jigs. I also have powders that cure at 350 degree's, and they're not the same so I adjust as is needed. I use an oven and I set the temperatures using a calibrated oven thermometer. Some use other heating methods and that's fine as long as that works for them, but to me the oven is just as practical and I have better control of the temperatures. I paid $35 for my oven new and have been told, by others, I can't afford an oven, yet they'll pay $30 for a heat gun!
Another thing that I do, is dip everything in acetone prior to coating and heating, to remove any oils, and allow them to dry completely. Powder paints are basically a thermoplastic, and the base metal needs to be clean, or it can't bond to it. Even the oil from your fingers can affect the bond of the powder to the lead, and this is a quick and cheap way to fix that as a potential problem. It's also another thing I read nothing about when folks make comments. I have read alcohol recommended for this too, but alcohol will not remove all oils, plus it has some water in it. It will dry with the heat, but will also leave a residue. I sell jigs, and I want them to last for my customers. They're not indestructible, but I don't get any complaints either. IMO, most folks who have problems with powder coat, create their own problems. The process is simple, but it can be fouled up by doing things that contradict good sense.
That's how you get good results with powder coat, do the common sense things and be consistent in your process, and adjust only if needed.
I've been using these powders for about 25 years, so I've had a good bit of experience with them, and I certainly have learned some of this the hard way, by making these mistakes. Only a fool continues to make the same mistakes over & over.
