Phosphoric Acid Metal Prep

[GregT]

The traditional - and illegal - way of disposal is to put it on a trailer and go out into the country to a gravel road. Stop, puncture the drum and drive slowly for long enough to drain the container.

Legally, I think some city refuse centers can take hazardous liquid waste. For a price.

Otherwise sell it. Then it's someone else's problem.

[ThePog]

8 minutes ago, GregT said:

The traditional - and illegal - way of disposal is to put it on a trailer and go out into the country to a gravel road. Stop, puncture the drum and drive slowly for long enough to drain the container.

Legally, I think some city refuse centers can take hazardous liquid waste. For a price.

Otherwise sell it. Then it's someone else's problem.

 

Im unhappy with the thought it might get used for nefarious purposes if I sold it to a rando.

I did find a hazardous materials disposal place, they said they would take it for $$.

[GregT]

Might be worth a call to any radiator repair places locally. Maybe someone doing restoration work too.

[ThePog]

yea I might ring around...

[dmulally]

Throw it at a series land rover and record the results. 

[cubastreet]

Parkerise the series landie.

 

[BiTurbo228]

On 18/06/2024 at 00:16, ThePog said:

Ah man I have a 20l of 99% phosphoric somewhere that i inherited when I bought a business, I moved it when tidying up my container in the pandemic and it had a small crack in the container. This was enough to react with the wooden floor and set the container on fire. It sat outside til I could wash the container floor and find a new container, and where it sat and leaked a bit more the ground bulged up around it. How I didnt get any on me is miraculous.

I have no fucking idea what to do with it..

Dilute it down into 10% solution and sell it as rust converter on gumtree (is it still gumtree in New Zealand or is that more of an Australian thing). Remember add acid to water, not water to acid.

Oh, and I don't know how much dairying there is in New Zealand but phosphoric acid gets used for cleaning farming equipment as 'milkstone remover'. Generally a lot more affordable that way than buying proprietary rust converters that are pretty much the same thing.

[lowlancer]

Bumping this back up,

For those of us who don't have access to, or a desire to spray massively hazardous shit in their garage, but would also like to deal with treating rust and bare metal, what are the best products and processes others have used?

It's interesting to read about it all, but also easy to get confused/lost, so a little clarity in an NZ OS context would be cool.

[Spencer]

Many ways to go about it, some quick cliff notes below. Ask more stz for more detail.

You can use abrasive methods, sand blasting is number one gives you clean parts no rust basically ready to paint. Then down the list you can use wire wheels, stripping discs, sand paper. This gets messy but works well, need lots of labour to get it all clean "white" metal after which is what you want to paint on (as in the wire wheel etc can leave lots of material that needs to be sanded clean after).

Chemical you can use paint stripper, if you do lots of prep work it can be pretty clean, works great on old single stage paint and shit on modern 2k paint.

Chemical rust treatment you want to use acid and you absolutely cannot use it on cast or high tensile parts it will ruin them. Buy some rannex from bunnings, you can dilute it in a big bath and soak parts (keep your eye on them) or you can follow the directions and spot treat areas. Again after you want to scrub down with scotch brite and clean things to white metal after soaking.

You are in for a bunch of manual labour any way you go about it hence you should weigh up dropping off parts at the blaster man its more efficient paying for it and its perfect result, they will even paint it in a zinc epoxy primer. The stuff you cannot drop off you will be in for time to manually grind/sand it or chemical treat it. I like the acid bath, very weak solution and leave over night, then sand and paint with epoxy primer.

Don't use any rust conversion primers or paints they are shit.

For the hazardous shit comment I take it you mean for the paint? IMO you have to stump up and paint with modern shit like epoxy primer (which is fine to spray at home, you could brush or roll it on if you had to) then some top coating. Top coating is the harder DIY part, modern paint to use is 2K urethane which has the bad stuff in it isocyanate, however if the car is lacquer and you are keeping that you can touch up over epoxy with shitty 1K paint. Doing a bunch of rust repairs and then painting it with rattle cans is the biggest waste of time ever so don't do that, do epoxy primer then shit 1K top coat at a minimum.

 

[lowlancer]

@Spencer that's primo, thanks man. What are some examples of the common rust conversion primers to avoid? They seem to be everywhere.

From what I'm reading, the phosphoric acid shouldn't really be brushed on/allowed to dry and it's a remover, not a convertor of rust - is that correct? In which case, I assume this is the same way say vinegar functions to remove rust? Which follows that the stripping method (sandblasting/paint stripper/wire wheel combos) should be used first to remove the paint and existing heavily rusted areas?

Lastly (noob as question but I'm too old to care about looking dumb) - if you're just doing a small area, is it ok to use an aerosol-based epoxy primer, assuming they exist?

Thanks for the info. Legend.

[Nominal]

Oh boy, you have summoned the speeno rust demon

Phosphoric acid does act on the rust chemically. I've let it dry plenty of times, it can be cleaned up by wetting with more/sanding. The main thing is that if you want a long-lasting job all the rust etc must be gone (clean white metal) before the epoxy primer.

[Bling]

I used rattle cans top coat because I can't spray properly, never cared about finish and it lives inside so not worried. Yeah agreed it's pretty shit, but I did what I could with the budget I had. If doing small areas just mix up small amount of epoxy primer. At least that's what I did, most of it was hidden eventually so I made some pretty small amounts (measuring cups from proper paintshop make this easy) to do small repairs as I finished them. I had halfmask with organic filters (sealed when not being used, they don't last forever) for even just brushing the stuff on. You know it's good if it puts hairs on your hairs on your chest just getting a small sniff.

[lowlancer]

@Bling @Nominal @Spencer

Thanks guys. Is there a thread dedicated to all this? Be great to get feedback on process for certain areas and best methods be it for time, cost or overall quality of result.

[Nominal]

6 minutes ago, lowlancer said:

@Bling @Nominal @Spencer

Thanks guys. Is there a thread dedicated to all this? Be great to get feedback on process for certain areas and best methods be it for time, cost or overall quality of result.

It's a long thread, but there is some good stuff in there

 

[Spencer]

The paint thread, but we have worn over the same topics 100 times its a roller coaster.

Avoid all rust conversion primers, they are all shit.

yes remove paint first, paint stripper or the sanding methods whatever works.

Acid basically eats the rust off the steel (and eventually the steel itself), you can use all grades of acid. You can use citric acid for big baths, its cheap for high volume, its similar to using vinegar as in its slow as fuck but its cheaper both are weak acids. Skip that though and get phosphoric acid from bunnings (or somewhere else cheaper) you can use it neat and it will treat quickly as its quite strong (as per instructions) or you can water it down and bath parts in it. Again anything cast will melt, high tensile bolts will be ruined, we are talking shit steel panels and parts only.

I am a fan of soaking parts in acid etc but if we are talking on the main car body usually get the grinder out so you don't have the mess of acid in body seams and gaps etc. You cannot really clean out the acid if you get it in body seams and it will start reacting again every time its wet or damp. So for that reason I usually only bath parts that come off and fit in a bath, its slow/quiet and low labour for those bits, I just did another lawn mower like that it is amazing for that job. Its also good on a pitted big panel like a roof maybe, internal floors or doors not so much.

As said make sure the steel is "white" before you paint, the finish you get from sanding or I usually scrub with green scotch bright pad (you get from paint suppllier in a roll). You do not want to paint on gray acid treated steel or gray steel after grinding/wheeling you will see this when you scrub  them up after. This is lots of work getting panels clean even after grinding and acid dipping, still have to scrub them all clean.

Don't spray the can epoxy you need 2 part, go to a pain shop get 1L kit and paint cups to mix it. Get all your repairs clean at once, then brush it on (or spray with a 3M normal mask its fine). You can sand the epoxy primer then use some shit rattle can top coat paint to cap it off, this is like minimum viable process. IF you can use 2k top coats the durability of the repair is like 100x.

If you can get shit blasted and primed then do it. Obviously if its the body and its not a ground up resto then DIY methods it is.

[lowlancer]

@Spencer cheers, I had a look through that thread and had to laugh at you slowly losing your patience with people asking the same questions... then me over here doing it all over again. Way, way clearer now, gonna get stuck in and have a crack.

Will eventually have to buy a compressor and gun etc, and a welder, so will have a good hoon through that thread when the time comes.