Posted 2013-04-07 1:17 PM (#151144) Subject: Muriatic Acid floor wash - did I do it right?
Member
Posts: 9
Location: Rochester, NY
I just did a Muriatic acid wash to the floor of my aluminum horse trailer as there was some corrosion. I intend to coat it with truck bed paint.
Is this how it is supposed to look when done? I guess I had the impression it would be all shiny/smooth but it is dull and has a chalky texture. I just want to make sure I did it right before I paint over it... I am a first-time horse trailer owner. I used the "green" "low-fumes" version of the Muriatic acid sold at Lowes.
All of them were taken about an hour or two after I did the wash when the floor was still a bit damp, with the exception of the last two which were taken this morning (dry).
Posted 2013-04-07 2:35 PM (#151147 - in reply to #151145) Subject: RE: Muriatic Acid floor wash - did I do it right?
Member
Posts: 9
Location: Rochester, NY
I did scrub it with both a broom and a hand scrub brush after the acid had been on about 10 min. It's just a chalky texture, no loose powder. Is it supposed to be smooth?
Posted 2013-04-07 10:33 PM (#151162 - in reply to #151144) Subject: RE: Muriatic Acid floor wash - did I do it right?
Expert
Posts: 5870 Location: western PA
If the acid is still bubbling on a second coating, it's an indication that the area is still oxidized and has corrosion. When the acid no longer reacts, (actively bubbling) then you're done with the application. Usually this will not occur over the entire area, normally just where there is more intense corrosion. Scrub well with a still bristle brush, like one used for a roof coating. Do not use a hand brush, you want to keep your face well out of the acid's fumes.
The resulting surface will not be shiny and smooth. The acid etches the surface, making micro pits that aid in a surface coating ability to better adhere. Because of the age of the metal and its uneven wear, it will also not be exactly the same colouration over its entire surface.
Sorry I didn't get a chance to answer your PM. Do not use automotive undercoating material to coat the floor's surface. A bed liner material is completely different and is far superior in durability and function. Any brown, black or gray spots are an indication of corrosion and should be spot coated and activated until the colours dissipate.
Make sure that the acid treated area is completely flushed with water and dry before any material is applied. It may take two or three water applications with a pressure washer to completely flush the acid. Failure to do so, may inhibit the bed liner material from completely adhering.
Posted 2013-04-08 3:44 PM (#151184 - in reply to #151144) Subject: RE: Muriatic Acid floor wash - did I do it right?
Veteran
Posts: 218 Location: Ohio
Make sure you really wash out the acid when you are done. There has been much internet writing on Truck Stop washes using acid and if it is not flushed well, the fumes can leach back into the horse area and has made live stock ill.
Acid works well but you have to be careful.
Posted 2013-04-17 4:27 PM (#151368 - in reply to #151162) Subject: RE: Muriatic Acid floor wash - did I do it right?
Member
Posts: 9
Location: Rochester, NY
I didn't have a pressure washer so I just bought one at Walmart. It's electric and 1300 psi, not very high...is it ok for this purpose though or should I consider renting one?
Posted 2013-04-17 11:21 PM (#151378 - in reply to #151144) Subject: RE: Muriatic Acid floor wash - did I do it right?
Expert
Posts: 5870 Location: western PA
A pressure washer is very handy for many uses. It will work fine to flush the trailer's flooring, but that should have been done while the acid was still wet.
I had an electric washer for a few years that put out about 1800 PSI. It was OK for quick small jobs. I often used it to clean out fiberglass boat molds. One day I tried to use it to wash the interior walls of the arena. Used constantly, the pump motor burnt up after about 45 minutes of continuous usage.
We now have a gas 2800 PSI washer and the difference is remarkable. I can blast rust scale off of metal. It's only limiting factor is a relatively small gas tank.
A small unit will suffice for some efforts. If you also want to use it for larger projects such as a deck or building, it's capabilities are limited and you might become disappointed with its performance and longevity. The closer you can get to 1800-2500 PSI, the more useful it becomes.
The difference in pricing between a high output electric and a basic gas washer can be relatively small. I now favour the gas.
Posted 2013-04-19 1:35 PM (#151415 - in reply to #151144) Subject: RE: Muriatic Acid floor wash - did I do it right?
Member
Posts: 9
Location: Rochester, NY
Well I flushed it out what I thought was very thoroughly with just a hose, but a day or two later when it dried the entire surface had a light coating of white chalky substance, so I figured I must not have flushed it out well enough.
I bought a pressure washer and did the wash again, pressure washed it thoroughly after and the same thing happened a day or two later.
And it continues to bubble every time I wash. I don't know why.
Posted 2013-04-19 8:15 PM (#151426 - in reply to #151144) Subject: RE: Muriatic Acid floor wash - did I do it right?
Expert
Posts: 5870 Location: western PA
If it continues to bubble, the acid hasn't removed all of the corrosion. You are using muriatic acid, aren't you? It may take two applications, rarely three
Muriatic Acid floor wash - did I do it right?
