galvanized steel/plate

[Shedendman]

Didn't know where to ask this...................so here goes
I have some gal plate i want to weld up to more gal plate,in other words i've loads of 1.5mm thickness but need to make up some 6mm thickness(its for the hotplate on a woodburner) now i know that galvanize is nawty stuff to weld with so how much of the coating do i need to grind/sand off,back to shiney steel ie gone the dull hammer/fish scale effect,i dont want to use a grinding disc as this is far to rough,sanding disc with 80 grit perhaps??????

Another thing i intend drilling loads of 6mm holes in 3 of the plates place them on the 4th and plug weld them then do the edges this a good idea????????

So basically 4 bits of 1.5mm sandwich together to make a 6mm plate

All ideas welcome

 

[the snooper]

if you are using a sanding disc on a grinder just keep going until you get sparks the you will know the galv has gone

 

[Shedendman]

Yer as i thought ta,but i'll be using a sanding disc on a rubber back att with a drill

 

[the snooper]

yous hould still get some sparks

 

[PTvor]

Leave it in dilute hydrochloric acid and it fizzes until the zinc is eaten away.

Where do you get hydrochloric acid (spirits of salt) in the UK easily?

I've seen small bottles in a builder's merchant here, but mine came from France where you find 1L bottles of 27% HCl for about a Euro in the supermarkets, just another household chemical. I diluted it about 4 to 1 and it got rid of the zinc on some galvanised pipe in two or three hours.

 

[awemawson]

If the 1.5mm sheet is in good nick I'll swop it for a slab of 9 mm that would be far better for your hot plate.

I'm TN33 0RG for probably not far from you

 

[Drains]

Stalwart, that's a really nasty thing to want to do. If it wasn't galvanised it would be a crap job (scuse the French), with galv, it's too horrible for words. Why? Well a stove top should be solid, not laminated with voids and air and stuff, and with galv, every time you get the stove reasonably hot you'll poison yourself.

Think again, stop being so desperate (you sad git), buy/acquire some plate. awwmawson's offer is not one to refuse! If that doesn't work out, go to your local metalwork shop, tell them what you're trying to do, they'll groan, take pity on you and give you a bit of plate, believing they have saved some poor deluded fool from absurd DIY sufferance.

 

[chunkolini]

sounds well dodgy to me without the galv business.
As a lamniate it will expand and warp all over the place,
definitely go find a piece of plate. Then you have to cut it.....

Chunko'.

 

[Welderpaul]

I could taste the galv fumes just reading this.

 

[Hitch]

Agreed, bad idea, right up there with using galv mesh for bbq shelves

 

[the snooper]

you just cant cut corners on some things

 

[Shedendman]

Blimey feels like i've had a right telling off,but thanks for all the advice anyway.
Can i just say in my OP i did say i wanted to sand/grind all the nasty stuff off to which i have done right back to shiney steel then washed with phosphoric acid well etching acid which is 60% phos based.

Now today(@ 12pm) i've drilled holes all over it about 30mm apart through 3 sheets and pluged weld these all up to the 4th and the edges not one bit of whispy white smoke at all nor do i at this time 19.41 do i feel ill(yet,lol)
i did read summit about drinking milk,is that true?

As for it going inside any building,no way its gonna have at least several burns out in the open 1st,loads of dry rot floor boards/joists to dispose of.

Now the warping matter,yep i did think of this but i'm gonna take a gamble from the way i've stuck it together and see, if it goes breast upwards then yes i'll go in the stocks and prepare for all the rotten fruit and veg you lot have

desperate,maybe,sad git,never

Oh one last thing,i did go to a metalwork shop one i go to quite a bit who always let me rumage around the waste bins,got met with this
"sorry m8,cant atm things are that bad what we put in the skip we weigh in for scrap,as its paying the rent on this place"

Blimey,times are hard

 

[outofthefire]

Offer to pay for the bits out of the skip pay scrap value and you'll both win