Hi Jay,
Hope all is well with you and the family.
Please don't store muriatic acid in your garage. If you do, you need to be ready for rust and damage and disappointment. I learned this the hard way. It will cause all your steel tools to rust, shovels, cars, nails, bolts, even chrome. Don't buy more than you need because this stuff is a real problem to store. And ALWAYS store it in a plastic bottle with a plastic lid. I've seen the stuff completely dissolve the metal top of a glass Ball jar in a few weeks...just the fumes of it. Now I should tell you even stored in a plastic bottle this stuff will cause rust on tools, etc. I used to use this in metal plating and it is one tough chemical to keep around your house. I don't have one, but friends with swimming pools tell me they can't store it in their sheds for the same reasons.
And never ever drop anything made of aluminum into muriatic acid. Any aluminum (even aluminum foil, pop cans, etc) will have a thin oxidized layer on it. Once the acid dissolves this oxidized layer and gets to the bare aluminum, then chemically speaking all hell breaks loose.
As an alternative, strong vinegar (any percentage higher than about 12~15%) will break down rust and dissolve it. It is also a decent carb cleaner, but I wouldn't leave a carb sitting in it too long because vinegar is essentially just acetic acid diluted with water and some acids are not good for pot metal. You can actually watch dirt and stuff bubble out of carb passages, etc. When you're through, filter the trash out of it with a coffee filter, put it in a Windex bottle and spray it on weeds or thistle in your sidewalk cracks. Sprinkle a bit of salt on the base of the really resistant ones and in about 3 hours they'll be dead as hammers. Of course any plant you put vinegar and salt on will die, so don't put this on weeds in your grass. And vinegar can be stored much more safely than muriatic acid.
