If you used Nitromores on steel, do you have to use/treat the surface pre-powdercoating? If so- what with?

surely the powder coaters will know what's required? give 'em a call

Have you not been here recently Hora, let the powdercoaters strip it, they will have a chemical dip or a blast cabinet and even if you strip it yourself they will either blast or dip it anyway to give them the correct surface finish for powdercoating.

nitromors is alkali so after lots of flushing with water, a vinegar rinse would do it nicely.

Vinegar? Ta. Checked with Powdercoater- fine but I wanted to doublecheck incase the lad on the phone was fobbing me off/bored 😉

nitromors is alkali

It shouldn't be, it's just a mix of DCM and methanol – couple of % other thingies in there but it's basically solvent.
Don't get it on your skin/floor/any painted material that needs to stay painted and don't flush it down the drain either, it's very toxic in water.
Just wash it off with water afterwards.

I will refer you to the SSPC SP1 standard – solvent cleaning. I'm just starting a NACE course 🙁

Personally I'd use some hot water and a sponge then dry it. Acid is just going to increase the chances of rusting or leaving the surface acidic. which will cause premature coating failure.

Solvent wash is an option but the solvents aren't nice or easy to get hold of.

Soapy water and then hot water washdown in the back yard and of course the dog not allowed out there for a few days afterwards.

If your going to leave it unpainted for a few days I'd rub it over with a bit of oil. Not much, just a bit on a rag to stop it rusting.
The coaters should lightly blast it to give the powder a key, this will remove the oil.

if coaters can remove oil then they can also remove the rust so i cant see it making much difference.

don't put oil on it before it's going for paint and prep, blasting and oil doesn't mix – a nightmare for you and the painters'.

Leave it, clean it with water, then solvent, store in a dry place. It will rust if you just clean it with water. I've done a fair volume of it in my work http://www.peterflynnclassiccars.com

Don't put oil on it. Let it rust if you must. Blasting will remove rust but not oil. If you store it somewhere dry then it won't rust that quickly anyway. We store blasted steel wrapped in dry rags for upto 4 days with no issue and we specify SA (2 1/2 to) 3 which is the highest level of blast cleaning possible.

Could be wrong I thought nitromors contained caustic soda…

Could be wrong I thought nitromors contained caustic soda

Go on. What does that do to steel?

No CS AFAIK, it's Methylene Chloride and Methanol. Do NOT wash it down the drain, very unpleasant stuff. Why can't you get it shot blasted Mark?

They dont have the facility to shotblast. I also thought shotblasting 'thins' unevenly the already think steel diameter main tubing if the person doesnt pay enough attention?

jesus…

Nitromors is solvent based, some of the versions contains DMC and some don't (just MeOH with a few additives like SLS), the ones containing the DMC are better at stripping paint but are a lot nastier to handle.

Caustic soda (aka NaOH) will slowly dissolve a steel frame, we are talking bloody ages here mind. If it was an aluminium frame you could add dye and colour the frame but you have to be careful as NaOH rips into the reactive aluminium as it strips off the protective oxide layer.

As for the shotblasting, if you have a thin walled aluminium frame like some of the merida shotgun tubing stuff then you could damage it. With steel this is much reduced, if it's that much of a worry there are places that use different abrasives (like ground walnut shells).

Have a word with the people who are powder coating your frame – ask them what to do, if they cannot shotblast the frame I presume they have a chemical cleaner to strip the frame of residue?

If not, go somewhere else because the job you are about to get done will be shite and last about as long as you generally own most of your equipment (4 weeks).

They must have some way of stripping stuff before they powdercoat, surely? A frame could be grit blasted without issue I imagine, bit like blasting with sandpaper.

What wrong with letting the powdercoater strip it for you?

I just had a Scandal stripped and powdercoated, they had 2 methods where I went either blast or chemical dip, no problems on an ally frame and it certainly wont be any trouble on a steel one.

You could happily waste your life stripping it, but he will still do something else to it before he coats it or the finish will be pants, just let them do it.

I presume he's doing this at a bog standard engineering/metalworking place – one that only coats new metal.

So they should have a solvent bath to clean hand residues and the like, but not the ability to remove previous coatings before they coat it.

If saccades is right, just go somewhere else, there are thousands of em over the country, the bloke I used would do it postal if you wanted.

DCM and Methanol in Nitromors, no mention of sodium hydroxide on the tin.

(Chemistry pedant: it's Dichloromethane we stopped using methylene chloride a wee while ago)

Hora I'm sure they do something to the metal before powder coating. I know my old frame went through three processes. One was to prep the frame, then the coating then a clear resin? coat.
I used Nitromors on mine prior to the paintjob, I never had any issues.

Cool, no caustic in nitromors then good to know. If I had a tin I would have known.
I used to use caustic soda to strip motorcycle parts before rattle can spray jobs when I was a teen moped freek, only because I had a free supply of it and I thought that was the stuff in nitromors…. 🙂 Imagine 25 years of ignorance fixed on STW in a couple of hours.

I think they changed the formulation of nitromors to remove the DCM. I'm not walking into the lab to check though.

As for blasting it depends what they are doing and who's doing it. You can use different shot or grit that is not as hard so won't remove as much steel. You don't remove that much steel anyway to get a profile, unless you hold it in the same spot for minutes. The biggest problem is the pressure/force which can bend metal.

There are different types of powder coating (it's another department so I know very little) epoxy systems are common and they might have an anti corrosive primer underneath. The only thing I can think to put on top is somethink that's more UV durable as epoxies are known to break down in UV over time.

NITORMORS ALL PURPOSE PAINT & VARNISH REMOVER
COMPOSITION
Name EC No. CAS-No. Content Classification *
Dichloromethane 200-838-9 75-09-2 60-100% Carc3; R40
Methanol 200-659-6 67-56-1 5-10% F; R11 T; R23/24/25, R39/23/24/25
White Spirit 265-185-4 64742-82-1 1-5% Xn; R65. N; R51/53. R10.R66.

like I said – there are several different variations of Nitromors that you can buy, some with and some without dichloromethane.

I presume he's doing this at a bog standard engineering/metalworking place – one that only coats new metal.

So they should have a solvent bath to clean hand residues and the like, but not the ability to remove previous coatings before they coat it.

In one.

Bit of info (maybe obvious to some).

Nitromores acts 'sluggishly' in cold temperatures. Took a fair few coats on parts along with a wire brush due to the sub-zero temperatures in my back garden.

Even though I had a rag over my face Im still high as a kite 😐

a rag over your face is going to do **** all with a solvent vapor. You need an activated carbon ori-nasal mask and suitable and sufficient ventilation. Well done you've survived using it there have been serious ill health consequences of joe public using DCM strippers at home in poorly ventilated areas. Don't get it on your skin either as it readily absorbs and can give systemic effects.

If you don't know what you are doing with chemicals don't **** about with them.

just a little bit of toxicology data
DCM
Harmful if swallowed or inhaled. May be harmful by skin contact. Eye and skin irritant. Readily absorbed through the skin. Asphyxiant. Causes CNS depression. Possibly carcinogenic in humans. Possible mutagen. Experimental reproductive effects.

sweet dreams

Oops! Still we've all got to go someway/sometime/somehow you big Cassandra

Experimental reproductive effects.

😯

occupational hazard of health and safety consultancy – sorry 😀

crazy-legs – Member

don't flush it down the drain either, it's very toxic in water.

Just wash it off with water afterwards.

How does the latter get round the former?

Experimental reproductive effects.

Say hi to my Son..

Say hi to my Son.

looks like he rides a single speed