Once again there have been discussions about treating aluminum flooring with Muriatic acid. The process is relatively easy and inexpensive, and is an excellent preparation for any coating you may want to apply. However as has been noted, the acid produces some noxious fumes when used to treat aluminum flooring.

A proper respirator is necessary. I have been asked if the paper type with a rubber band will work, or if just holding a piece of cloth over your mouth would suffice. When I treated my first trailer floor, I didn't use any respirator. By holding my breath and working a minute or so at a time, I ran in and out of the trailer multiple times. Paper and breath holding are not proper preventions for the affects of acid fumes.

The proper respirator for this job is one designed for "organic vapors". It will be a mask that covers your mouth and nose and  has replaceable cartridges. The cartirdges usually contain finely ground activated charcoal, that provide a relatively large amount of surface area to absorb the fumes. They are available at many locations including Sears, and are made by a variety of manufacturers including 3M. Prices start at less than $30 and go up from there.

I've been to several schools for painting, using acid strippers and industrial chemicals. One of the most important lessons I learned was about the products' smell. When you are using a respirator, you can still smell some of the product from which you are protected. When, or if, you realize that you cannot smell it any more, you must immediately leave the area to a fresh air source. Most people would think that the respirator was doing a great job and continue their work.

I am not a doctor and don't know the proper medical terms. Your body has many sensors that detect taste and smell. When they are subjected to prolonged levels of noxious fumes, they can become temporarly damaged. When you can no longer detect the odor, they have shut down. Continuing the exposure can cause permanent damage.

The advantage of these types of respirators is that the cartiridges are replaceable. Unlike a paper filter used by a wood worker that collects dust on the surface, the charcole is used up and has a finite life. Depending upon the chemicals, they may last a few hours or only part of one. New filters are available for a few dollars each and the mask is reusable. They can be used when you're spray painting, using harsh chemicals or cleaning unwelcomed odors. Having one available is quite handy.

Now that I've frightened you from ever using Muriatic acid again, remember that this job involves short exposure times, and by using the proper respirator, most of the dangers are minimized. Like any job, having the correct tool will make the process safer and easier.

Gard,would that also be one reason that your directions are to do the floor in 3 sections separately? Or not?

I kinda had to chuckle at the image of you running in/out of the trailer those multiple times.WOuld be hard to get one finished in a day's time like that,right? But good exercise!

Gard as you have said before with this process,this is only necessary if there is corrosion that has begun on the flooring,right? And this is most readily identified by a powdery appearance rather than just blackened areas?

I've recently ordered a new Hart trailer, and plan on coating the floor before I use it.  It will never have had a horse in it when I do this.  Do I still need the acid wash step to etch the floor for good coating adhesion?  Or can I skip this step?

During the manufacture of a trailer and its components, various lubricants are used, welds contaminated the joints, worker's hands left oily prints, and rags smeared various products onto many surfaces. Just because a new trailer is shiny, doesn't mean its surfaces are free of contaminates. Some manufacturers will acid wash a trailer after it is completed. This helps, but how many people walked on the flooring afterward? Was a new mat with its various chemicals placed on top of the flooring? What oils were in the parking lot, that were picked up on the soles of various shoes? What petroleum products were transfered from the black top surface of the storage facility?

Aluminum is a difficult material to coat. Its surface must be properly prepared and absolutely clean to effect a lasting bond. Any short cuts here will show up in the future.

Well,oops.Sorry for re-asking the same ?.Since I've been through chemo and on followup meds,my memory isn't that great anymore.Please excuse.