Muriatic Acid??

[Rhodes]

I just bought some muriatic acid to clean out a couple metal tanks but I have no idea how long to leave it in the tank.

[harryredtrike]

till its clean

[atc350xer]

If it makes holes in the sides, you waited too long :lol:
Seriously though, I'd put it in, wait 10 minutes, and have a look... dump it into a plastic bucket if you need to, then dump it back in if it didn't clean it good. How long really depends on the dilution and how rusty your tank is...

[200XMichigan]

I usually dilute it 1/2 water. Its a good idea to have some baking soda mixed in water to neutralize the tank after dumping out the acid and flushing it with water. Otherwise it will flash rust. Also you can put the acid back in something and reuse it. Its strong enough to do a lot of tanks.

[250RWANTER]

I cleaned my tank the other night with this acid and flushed it with fresh gas and emptied it again. It looked brand new inside. I just opened it up to have a look and it is all surface rusted again. You are saying if I mix some baking soda and water to rinse it with, that will prevent it from rusting so quickly? How much baking soda do you use?
thanks!

[Dirtcrasher]

Dilute it as said and it does flash rust. You almost HAVE to KREEM or RED-COTE it right after your done..............

[tri again]

i had a tank that looked as smooth as asphalt inside and since it was toast anyway, I used muriatic acid full strength and it smoked!!!!!!!!!!

do NOT breathe that crap.

dilute 1/2 with water and let it sit say 1/2 hr, shake around some rocks inside and then run a hose for 10 min or so and also dump in 1/4 box of baking soda. and shake some more.

always add acid to water NOT the other way around and never add baking soda to acid.
wait until the water has diluted it

if you want to see the harmless version of this reaction, pour a little vinegar into some bake soda

if it makes pinholes, you were gonna get them soon anyway.

after the flush, I ran a hairdryer in there to dry it and then sprayed in some non wd40 and closed the cap

I heard that propane would also displace oxygen. since its heavier than air

i usuallt run a foot of clear fuelline and let it loop down so crap settles in the bottom of the loop because that flash rust dust can plug a new fuel filter and it will still look new

radiator shops can clean them cheaply too and even fix leaks

[Thorpe]

I always wash with straight muratic acid... Then go to a por-15 tank kit...

[200XMichigan]

Make sure to remove the petcock...acid will dissolve aluminum.

I usually use a whole box a baking soda to prevent the flash rust. I will let that sit in there for 10 min or so. The best idea is to coat it after you clean it. RedCoat or Por15, people seem to like. I used Kreem and it worked but the results look sloppy.

You can coat it with oil or penetrating oil and if you neutralize the tank it will not flash rust but the coating is best.