The problem with the premix is the cost. One Gal of Sherwin Williams Revive retails for 24.99. Contractor price is 19.95. Powdered OX is much less expensive. Thanks for the info on the stability. That’s always a concern.
I’ve used elemonator with oxalic acid to remove rust stains on walls. Be very careful of blue and yellow paints have had discoloration with both. Ended up hand brushing oxalic elemonator mix over an entire house to even out paint color on a house that went from a dark yellow to a much lighter yellow. Customer was happy with result as house was really badly stained looked freshly painted when done just no longer a dark yellow…
2 Likes
I bought a HF grinder many many years ago to get me through ONE small project because my father couldn’t find the one I lent him. I paid about $12 for it and I wasn’t very hopeful it would finish the 30 min job, well it did and ever since then it will not die. I purposely leave it outside to weather and die, well it won’t. It’s currently sitting in a few inches of water right now and I can guarantee you it will fire up tomorrow
1 Like
Loudest grinder I’ve ever owned lol
I’m resurrecting this old thread vs creating a new one. I have a GC customer of mine that put a roll off box(dumpster) in the customers driveway due to regulations on street parking. There’s now a rust stain in the driveway as you can see in the picture. I’ve dealt with rust stains on concrete before using rust remover plus, but the results were blotchy and not satisfactory. I have oxilac acid in stock in case any rust removal came up.
Brodie, did you do any scrubbing or brushing on the concrete slabs? How did you apply it? I plan on using .5 oz of clig on per gallon of mix. Do you treat the whole driveway in order to not have one section brighter then the other?
@MrSparkleVA I read your thread about using a roller to apply more evenly. Looks like you had some success with doing that. That thread is kinda old now. Do you have anything to add regarding this process that you’ve learned since then? I’m debating on using a pump up or roller. Looking for advice to shove me in one direction or another.
Rick, I just chimed you because I trust your judgment and you e give good advice every other time. Any tips?
As on right now, plan of action is: mix 1.5 cup oxilac per gallon of water w/ .5 cling on. Should I roll or spray? Full driveway or just up to breaks where rust stops?
Edit: if anyone else has something to add please do.
1 Like
When all else fails - F9
3 Likes
Guess I’ll have to place that order tonight then. I was trying to avoid it. Do you have a preferred vendor?
You can try some of the other stuff first, they may work. But no, whoever has best price but they all seem about the same unless running a sale.
1 Like
x2
As far as doing the entire driveway to get it to match, short answer is yes. If it matters. If it doesn’t matter just do the pad(s) affected. Just charge accordingly for your time.
2 Likes
IMO, you should do the entire driveway. If you only do the spot, then you will have the same effect just a different color. F9 or OA seem to not just remove the rust from the concrete but also lighten or whiten it as well. If you only do the rust spot then you will have the same shape stain but white compared to the rest of the driveway and to me at least would look just as bad…
1 Like
@Harold
No offense to F9…but dang that stuff is POWERFUL! I always worry when we bring hydrofluoric acid into the game.
I had a rust stain similar to that in my driveway…not as big but still similar. I know it’s not conventional, but what I did was hit it straight on with a toilet bowl cleaner…think of pretreating a gravy stain with a laundry spot remover…then I hit it with a garden hose. Again, I’m NOT a pressure washer, just a chemist…but if it’s a light rust stain, and toilet bowl cleaners are designed to remove rust stains…well, chemically speaking it made sense to me. Bonus that it was thick and stayed put for the 10 minutes I pretreated.
6 Likes
I’m going to try OA first. Thanks for your input. I’ll be cautious if I end up using the f9. If a chemist is nervous, I’m thinking I should be. 
2 Likes
That’s the problem I had with rust remover plus. The slab is fairly new, and I believe the GC is on the line for the rust stain. I’d love to save the day for the guy bc he’s a good customer but I can only do what the chemicals allow me to. I’m guessing there will be some type of liner under the box in the next driveway.
The concrete is low quality. I seen some cream coming off when I tested and had to nozzle down and treat.
1 Like
HF is one of the most deadly chemicals I deal with. Anyone see breaking bad? The thing they used to dissolve the guys body in the bathtub was HF. (side note, it ate through the bathtub too so don’t try that at home kids!)
Several people in our industry use Ammonium Bifluoride, it’s the safe HF alternative they say…um NOPE! ABF is HF in powdered and weaker form but use just 5% in a formula and your formula is now toxic and corrosive by DOT rules…anything that goes through your skin and eats your bones is something anyone should be afraid of in my opinion.
2 Likes
Tbh I have no idea what was in F9. I hear guys rave about the stuff so I’m sure it works, but it’s always good to know that I should proceed with caution.
What’s the actual mechanism of it HF working on rust? Is it dissolving the layer of the surface or just the residual metals that are staining the surface?
HF eats metal. Ever have an AMAZING aluminum brighter? It had HF in it. Nothing makes aluminum shine like HF.
2 Likes
Sweet. Now I can talk to the customer like I’m the chemist👨🔬
OA works the same way?
No, OA is far less aggressive…it works best on wood to brighten but it does that by almost bleaching the wood. It takes tannins (the things that make wood dark) and iron and turns them into a soluble material that can be rinsed away.
1 Like
Sounds like my OA plan won’t produce desired results.
Why? It, in theory, will remove the rust in the least aggressive manner.
1 Like
