Questions about masking and how the powder stays on

[UnorthodoxCreations Amateur Metal Finisher Find all posts View Profile Close UnorthodoxCreations]

My first question is about masking. Is it better to leave plugs, tape, etc on while baking or just take them off after coating. I read that taking them off off befre baking will leave a cleaner edge but is there any downside? Some stuff wont matter but on valve cover lettering and such I will want really clean edges. Removing them before baking also allows for cheap masks like regular tape, corks, etc.What are the advantages/disadvantages of each way?

Also I'm curious how the powder sticks to the piece after you have coated it and have taken the ground off to stick stuff in the oven. I mean it cant just fall of right? Do you have to be super careful not to touch or even bang the piece before its cured?

Got my oven, spray booth, and spraying rack tonight, gun, powder,etc should be here midweek. I cant wait to try it out.

Thanks
Adam

[sswee Metal Finishing Guru Find all posts View Profile Close sswee]

Re: Questions about masking and how the powder stays on

I can't answer on the masking because I have always left mine on till after cure.

The powder sticks rather well considering. It takes a little effort to knock it off. I bought a cheap roll of safety wire from the parts house, that I use to make tie offs to the part. It can be bent to get minimum contact with the part. Then use small s-hooks from a hardware store to hook the wire to the rack. I have accidently bumped the part putting it in the oven. Most of the time it is not bad and the powder will cover when it begins to flow. If there is a large bare spot, it is not hard to touch it up before curing. If I have alot to do I'll powder a part and hang it in the oven while I powder the next. I'll do this until the oven is full, then cure.

[pickleboy Metal Finishing Guru Find all posts View Profile Close pickleboy]

Re: Questions about masking and how the powder stays on

ok adam i will try to answer as much as i can. as for masking it can work both ways if you are doing something like a valve cover it may be better to remove the tape but if you scuff the powder it is a pain to remask to respray. i have done both ways with success. as for lettering i can also suggest this. if solid color is used and lettering is raised and to be uncoated you can spray the whole thing with no tape and then take a dry sponge and lightly brush the powder off the letters it does not have to be perfect but close. when fully cured and cool take some 1000 grit paper and touch up the letters. as for plugs it depends on the type of hole. if threaded it is best to leave them in. as the powder flows it can seap into the first thread and cause you to have to tap the hole to remove it then you risk chipping the surrounding powder. if a smooth hole it should flow out smooth if removed. as for other than high temp tape and plugs it goes with the above answers.
as for the powder sticking on the part after spray it will cling, but yes you need to be very careful not to bump the part or you can disturb the powder layer and cause a thin spot. just like a balloon rubbed on your hair and then stuck to a wall it will stay there for some time till the static charge dissapates, the same is true of the powder. if you get in a mind set that this is just as touchy as liquid paint before cure you will be ok. also right out of the oven the powder is still soft till it cools down so remove it and hang somewhere till cooled down. if the cure was correct it can then be put into service right then.
sorry for being long winded but i am anal that way. hope this helps out bro. and good luck when your stuff gets in.