Acid to remove galvanising?

[rtbcomp]

You can hire floor "planers" they take large diameter abrasive discs. People use them to strip paint & varnish off floorboards so they can varnish them.

If you stack the beams to form a floor as Normspanners suggested it shouldn't take too long.

 

[Kent]

Strong acids etc can do so much damage to your guys, I looked at doing a job recently and phoned a mate up for advice (an industrial chemist) after what he told me I just phoned the customer and said "thanks but no thanks". What he said about eyes was small gloves under big gloves and no goggles or visor off till you had them both off and washed, then do those hands again as your eye has no defence and it only takes a little bit of these strong chemicals to blind, the risk is more than one thinks as its natural to touch your eyes without thinking. So do a good risk assessment or sub it out IMO
I think I should be getting the 9" grinders out personally and just plain putting the time in on it, there are some right old qualified idiots specifying silly stuff on jobs today (book learning without enough hands on IMO)

 

[mike 109444]

What about a floor board sander fitted with an emery type belt rather than one for wood

 

[Welderpaul]

Agree i'd rather not go down the acid route, we have competent lads and can obviously use pvc suits, gauntlets, goggles, face shields etc but thats the last line of defence. Not keen.
Grindings not ideal either...even the best 9" grinders don't have a very long HAVS exposure time...theres hours and hours worth of grinding.

 

[Hitch]

24g belts rip the material off steel, and you've got the weight of the machine to push down on it... No where near as much of a problem with HAVS id say...
a minuite or so to swap belts... knock up a trolley specific to the job perhaps...You have a couple of linishers i believe?

 

[rtbcomp]

Flymo?

 

[Welderpaul]

Yeah, HAVS problem very much reduced as you don't need to bear the weight of the machine - just steer it.

I don't think either of our machines would let you use the bottom of the end roller, plus i wouldn't really want to disturb them - they are well set up with various stops angle gauges etc for doing tube. There's a few 2nd hand machines on ebay that i wouldnt mind butchering. Long legs, bear on the ground either side...straddle the beam.

 

[AndyStobbs]

What about modifying a cylinder head skimming rig to run along the rsj?

 

[MattF]

Off on a slight tangent, isn't hydrochloric the one where the fumes will also rust any exposed/bare metal they encounter? Another thing to consider if you go that route.

 

[captain-destructo]

silly question but howmany studs do you have to weld onto the beams in total?
could you not just take an extra couple of grease monkeys and grind the smallest area for each stud to be welded on or use the rotabroach idea?


will any of these work or am i just being thick

also what about a cold galvanising product for once you are finnished? (galvafroid??)

 

[DAPPH]

Had a bit of lateral thinking a few seconds ago .

Can you use electrolytic removal, using a thick paste electrolyte of something reasonably non too vicious to metal & humans like BICARB or washing soda , glue on or use self stick dense foam collars ,fill with paste attach correct electrodes and away you go etc. ?

I get the strong feeling that unless you grind deep into the metal there will still be zinc particles , for you'll melt some back into the scoured steel .


Perhaps it's worth while seeing what you can find on the internet.

 

[Tiggy_dorset]

A safer 'Acid' route would be, as Chunko has already mentioned, Citric Acid. Citric Acid is 'relatively' safe to use (we all eat the stuff).
Although a weak acid, it does work, but dont expect it to be done in 10 mins

 

[rtbcomp]

Off on a slight tangent, isn't hydrochloric the one where the fumes will also rust any exposed/bare metal they encounter? Another thing to consider if you go that route.

That's nitric acid. Hydrochloric acid on zinc gives hydrogen gas.

 

[sardine]

I use battery acid, which I have plenty of as I collect and weigh in batteries. It fizzes it off nicely and leaves steel bright clean. Fumes are nasty though.

 

[norlander]

I suppose in the current economic cli

I use battery acid, which I have plenty of as I collect and weigh in batteries. It fizzes it off nicely and leaves steel bright clean. Fumes are nasty though.

+1 on the fumes, I spilt some battery electrolyte on to the concrete floor and got hit by evil fumes almost instantly.FWIW I did an installation job in a workshop where they were doing galvo plating and it was a hideous place-hated galvo stuff ever since-its out to kill you

 

[normspanners]

Strap them all together side by side tow em down the motorway behind ya trailer
Then if stopped------- sorry when stopped ----say oh sorry they must have fell off and I didnt notice, it'll only cost you a little diesel!!

 

[mike os]

I cant see acid doing the job you want without immersion for several hours as I guess the coat is quite thick (relatively) and very hard to meet your hse and environmental responsibilities... a few little bits you could get away with but that lot???

modified linisher looks the best option so far....

 

[normspanners]

how about several of these

http://www.josco.com.au/newsite/jia/products/abrasives/abrasives_fwl.htm

side by side to the width of beam, mounted in a modified wood thickness'er/ plane you could then set the beam up on rollers and let it pull it's self through.
you would then just have to adjust the cut a little as the flaps wear, it could get on with it without massive input
http://www.ebay.co.uk/itm/scheppach...ies_Carpentry_Woodwork_ET&hash=item4ae189cc12
you could have a bit of dust extraction set up, use weld fume sucker?

 

[Liquid Metal]

Agree i'd rather not go down the acid route, we have competent lads and can obviously use pvc suits, gauntlets, goggles, face shields etc but thats the last line of defence. Not keen.
Grindings not ideal either...even the best 9" grinders don't have a very long HAVS exposure time...theres hours and hours worth of grinding.

Yes you have to take HAV into account and yes that would mean the guys doing it stopping every so often, or two guys, one taking over from the other every so often. So yes the labour cost is going to rise a bit, but why not just price this into the job and pass the increase in labour ont the customer??, rather than putting your employees at risk in a way that can be avoided (dont mean that nastily btw).

What is a better situation given the worst outcome with either method?? (if that makes sense lol )

1. Two guys taking half hour stints on the grinders, taking over from each other every half hour, so yes takes a little longer so company makes a bit less profit.
or
2. One saturday morning, two guys in the yard, paint the acid on, leave it for a bit, wash it of with a steam cleaner/pressure washer. Job done. But in the process, one get a faceful of the stuff somehow, and loses an eye, or ends up with severe burns to any part of his body??
Next thing you know, there are solicitors on the phone, letters from claims courts etc (i guess the loss of an eye wouldnt be just a 5,000 injury claim)
Also once they are aware of it, HSE enquiring as to what you are doing with the acid once its washed off, ie how you are collecting it and desposing of it so it doesnt go into the watercourse? I would have thought that would hit the business in the pocket too.


On the suject of grinders though, 7" with the Red 3M soft pads, 36grit cubitronic abrasive, dont give much vibration and rip through galv like nobdy's business.

Not sure if they come in bigger sizes, but 3M Green corps flexible grinding disks give same cutting degree as solid grinding disk with much muh less vibration

 

[sardine]

Is the dust created by grinding galvanising toxic ?