Hi Gard,

I cleaned the trailer floor with Aluminex (phosphoric acid) this past Sunday (so 3 days ago).  I didn't realize at the time that I should have cleaned the floor with muratic acid in preparation of sealing it.  Am I able to go back and re-clean the floor with muratic acid and if so what time frame is it safe to do it in.  I don't want to cause any damage or weaken the trailer floor by over etching or over cleaning. 

I want to seal the floor with the Herculiner/Duplicolor or whatever the the most updated sealer is that you recommend.  What is your latest recommendation?  Also, is there a clear sealer that would work?

Thanks so much for your help.

Kim

Thanks O WISE ONE!

The phosphoric acid is commonly used in rust conversion products for ferris materials. It turns the rust into an oxide, which then allows the metal's surface to be painted with little future rusting. One reason aluminum is so long lasting, is its ability to produce an oxidation coating which limits the amount of corrosion. Phosphoric acid can't work well over an oxidation, so it will have little affect on  an aluminum surface.

I assume that after the phosphoric acid was applied, the floor was then washed and allowed to dry. If it hasn't been washed, I would do so before another type of acid is applied. I'm not a chemist, so I don't know what type of reaction would occur, if the two acids were mixed together.

Apply the muriatic acid and proceed to agitate it strongly with a roofing broom. It may take two applications in some spots. When there is no further reaction to the acid, (bubbling/foaming etc) your acid application is finished. Make sure to rinse the area well and allow it to dry overnight.

The next day when you apply the bed liner material, DO NOT walk on the floor with shoes worn outside the trailer. It will contaminate the area. Put a door mat on the ground near your entry, and have some clean slippers or slip ons that can be exchanged and used only inside the trailer. I use just my socks after taking my shoes off.

The last three trailers I've coated for myself and friends have been covered with Duplicolor's "Bed Armor". It's a newer product than their standard bed liner material, which is very much like the Herculiner offering. It is available from many auto parts stores in our area. It has an additional kevlar material added to its water base. It is easy to clean up when wet, leaves a rougher durable surface, and can be applied over wood. It does cast about $25 more than the standard bed liner, ~ $75 for a kit. The kit provides several things you don't need, but I haven' found a source to purchase just the liner materials like their standard bed liners.

Hope you enjoy the results of your labours.

 I washed the horse section out very well last fall before putting the trailer away for the winter. Will I have to rewash before using the muriatic acid?

If the trailer hasn't been used and the floor is still clean, no you won't have to re wash. If there is any manure product left on the flooring, it will effectively mask that area from the acid, which you don't want it to do. The acid will then do a very good job etching and cleaning the flooring.

"OLD" Old is the operative word that increasingly becomes harder to ignore. It seems that everything becomes more difficult with age. "Wise" doesn't completely make up for the new found lack of ability. Best of luck with your project and have a great summer.

Thank you Gard for your help. 

When you asked if the floor was washed, do you mean with soap and water?  I used a pressure washer (no soap) to wash off the phosphoric acid and then allowed it to dry. 

Kim

By the way, there is a rebate available from bed armor...........

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Kim

When you asked if the floor was washed, do you mean with soap and water?  I used a pressure washer (no soap) to wash off the phosphoric acid and then allowed it to dry. 

No need for soap and water. The pressure washer is fine.

Gard - you are an amazing wealth of information. After 6 months of searching, I just bought my dream "upgrade" trailer. A true "BIG HORSE" trailer and a wonderful OLDER FEATHERLITE (2001 model, that is brand-new as in less than 500 miles on it)

It's so unused, that no horse has even pee'd in it, and the mats are all BRAND NEW looking, as is the very solid plank-type ALUMINUM floor (and it even has a drain hole at each "tail") This trailer is so well-constructed...I checked for everything when I looked at it. Crawled underneath and saw the floor supports were less than 12" apart! TONS OF THEM.

Anyways - there is zero corrosion or pitting on the floor - you could eat dinner off of it. But I plan to do the Muratic Acid wash, then the Paint On Bed Liner, per your advice :)

QUESTION: If a trailer floor is literally "unused" in new condition, but was manufactured in 2001.......you still need to do the muratic acid, right? I can't just pressure wash it and then do the bedliner? It has ZERO flaws/use/dirt/corrosion.

The muriatic acid does three things; cleans the flooring of contaminants; etches the flooring for a better surfacing adhesion; and stops any corrosion.

The trailer floor is now contaminated , even if it has had mats installed. During the manufacturing process, various chemicals are used, coating the metals. During the manufacturing process, many people entered the trailer, after walking across various surfaces. When the new mats were installed, the bottoms were not first washed and cleaned before they were dragged across the aluminum flooring. One person walking across a black top surface can contaminate a flooring enough, that his foot steps can result in a future surface bonding failure.

Aluminum has to be absolutely clean to be reliably coated with most materials. A one gallon can of acid and about an hour's labour, will ensure the best possible surface for bonding. If not done properly, many dollars and more work will be wasted, when the coating fails.

Dave, you didn't do anything wrong, there are no hard and fast rules. I suspect that perhaps the applied covering wasn't thick enough, and just needs more coatings. What did you use for the liner material?

With a coarse scotch brite or an 80 grit sand paper, I would abrade the corroded areas and remove any loose liner material, leaving the bare metal exposed. Then apply some muriatic acid to those areas and really agitate it until you have no more of a reaction. Rinse well and let the area completely dry. Apply more of the bed liner material, perhaps building the bare seam areas with at least three coatings. If you don't have any material left over in the gallon containers, most brands have rattle cans that make touch ups quick and easy.

I normally apply two heavy coatings, but I spot the high traffic areas with a third. This would be in the entry area, and where the horses feet are when they are standing in place. I've seen the liner weakened by constant wear, but not from a reaction to urine. Depending upon the brand you used, some materials can be recoated without anything more than first cleaning the liner's surface.

If you have to buy additional material for the fix, you might try a different brand. You can then test the results for the best outcome.

I've been researching muriatic acid and seems folks tend to add it to water. Can you comment? I'm sort of afraid to do this, but I really want to. I JUST GOT A NEW TO ME ALL ALUMINUM TRAILER :) And the floor is PRISTINE. It was only used once and no pee :) I want to protect it by using your method but am a little nervous :)

THANKS!