There's a lot of knowledge here so I thought this would be a good place to ask this question. I've been wanting to try either Mark Lee's or Art's Belgian blue solutions on a set of Parker barrels.

Since both of them have similar application & boiling processes, which of the two would you use & why?

I think Mark Lee works well, but can be frustrating if you don’t have a way to heat the barrels evenly.

Cannot comment on the other solution; I use Laurel Mtn. Forge, and also steam instead of boiling to convert the rust.

Good luck. It’s fun!

Just curious of what you mean by frustrating with un-even heat. What problems can be encountered if the heat isn't even?

Any & all helpful hint's & tip's will be appreciated.

Art's seems to have the Mercury BiChloride compound in it as did the orig Belgian Blue,,or at least the Art's Belg Blue did when it first came out and I tried it. I stop using it.

The merc will plate itself to any non-ferris metal you happen to have on the part. Usually not a problem. But if there happens to be any gold inlays, or brass inlay/sight ,,they'll come out 'silver' plated looking being tenaciously plated in mercury. It does not just wipe off.
On gold, silver or other precious metal inlays it has to be carefully polished off and any detail re-engraved generally.
A sight bead left in place can be polished back up a lot easier but it's still a pain.

The biggest drawback of Belgian Blue for me is that Mercury compound in the first place.
Yes it works great,,but the merc never goes away. It's in the carding dust and then in your shop, in your clothes, in you, ect.
Bad stuff. I spent way too many years using the older bluing solns with dangerous ingredients including this and am paying a price for it.
Stay away from it would be my advice.

I like MarkLee's for Express Rust blue. I warm the parts w/a propane torch. Don't get them so hot that the soln sizzles when applied. Just warm enough so it drys on contact as you brush or swab the soln up and down the bbl or part.

Too hot and the part can show some etching in that area. Not real bad generally,,but it does show in the final product if you are honest with yourself. Especially when trying to do a higher gloss polish rust blue. Those areas will be a slightly different shade of blue/black from the rest of the part because of the now difference in the metal finish underneath.

The orig way to Express Rust Blue was to put the part(s) in the boiling water tank and let them heat up that way.
They heat up evenly to just the temp of the water and no more. Take them out, shake dry and quickly apply the soln.
No hot spots to sizzle and pit,,but sometimes a cold spot or two on thin parts that you get to last. Reheat the problem part or area in the water or carefully warm them with the torch.

I use Laurel Mtn for Slow Rust Blue.
About as easy to control as it gets.

Thanks Kutter!!

The Mark Lee solution is intended to be applied to the barrels when they've been heated to a certain temp. If you've got an oven to uniformly heat the barrels, and can control the temp, the solution applies more consistently. I do not have an oven, so I have to resort to using a heat gun, which is difficult to get the a consistent heat along the entire length of the barrel. Not a deal breaker, but not as ideal as an oven of some sort.

When using those types of solutions and a heat gun or torch, have found it useful to overheat slightly, then wait a minute for the temperature to equalize.
Chuck