So I'm milling my first raw 80 and the instructions talk about installing the LPK and doing a function test prior to adding a finish. Not new to plating/anodizing on other projects, but I'm thinking I should I remove the LPK before dropping it in the bath?

Since the other parts are steel I'm worried about the corrosion factor from the sulfuric. I realize all I'd have to reintall is the trigger group, but the fewer times I have to install the better.

I get why you might leave the kit in for a cerakote since there is a thicker lining that could inhibit install, bit anodizing is only a couple micromils thick.

What does the hoard say?

Take everything out of it before it gets dropped in the anodizing bath or as you say, it is going to be a mess.  Installing an LPK only takes a few minutes.

My thoughts too. I'm guessing 80 arms is used to instructing people that try to use rustoleum to coat their end product.

I've had problems with non spec trigger holes, only real hesitation.

To be honest with you, I don't even finish the pockets on my builds and if it is a raw lower, I paint them, now remember if you finish it and then send it off for anodizing, you are going to have to send it to an FFL licensed company.

If you have a raw lower, I would look into blasting and using duracoat, it is a long lasting finish that works well for a lot of people.

I've done plating and electroforming, so gonna try my hand at anodizing. Have a decent recitifier, working on supply for the baths and dyes. If worse comes to worse I'll trash the idea and have a dealer in town cerakote it.

That's to keep you from finishing or anodizing it and then the parts don't fit and function, and you have to mill out a bit more or do some fitting and wreck the finish you've already done.  Of course they mean remove the parts before doing the finish.

You'll have to take ALL steel parts out before anodizing or they will be FUBAR during the anodizing process.

So leave the roll pins out during function testing to make assembly and disassembly easier on yourself. Just function test with the Fire control group, safety, takedown/pivot pins, and magazine release installed. Unless you bought the 80% lower from a truly shitty supplier, the bolt hold open and trigger guard features will install and work just fine later.

I recently tried anodizing aluminum with two types of drain cleaner instead of ordering chemicals to see if it would work. Lowe's and Home Depot sells sulfuric acid drain cleaner and sodium hydroxide drain cleaner. The sulfuric acid drain cleaner is extremely strong, stronger than battery acid but it usually has some color added and buffers to protect metal drains. The sodium hydroxide was the type sold as crystals.

The only problem I had was the sulfuric acid drain cleaner had some type of buffer in it to protect metal drains. After pulling my 1911 frame out of the sulfuric acid the dye wouldn't stick but a quick dip back in the sodium hydroxide solution took care of whatever it was and then the dye worked great.