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Welding galvanised steel.

Posted: Wed Jan 19, 2011 11:06 am
by MARKx4
This is not for a 4wd but i think it is the best place to get the info im after.

Im starting to build a back deck that is going to only sit a couple of inches off the groung. For this reason im going to be using 100x50x2.5mm galvanised steel.

I know welding gal isnt the best but im after techniques to do it to gain maximium penetration. I was thinking of grindint the areas back with a flap disk and then coat with cold gal spray paint.

Is there any better ways to do it?

Mark.

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 11:11 am
by tehekho
MARKx4 wrote:This is not for a 4wd but i think it is the best place to get the info im after.

Im starting to build a back deck that is going to only sit a couple of inches off the groung. For this reason im going to be using 100x50x2.5mm galvanised steel.

I know welding gal isnt the best but im after techniques to do it to gain maximium penetration. I was thinking of grindint the areas back with a flap disk and then coat with cold gal spray paint.

Is there any better ways to do it?

Mark.
I've never really had strength issues welding gal - then again I don't do a lot...

Just make sure you take a breather as that shyte makes you feel crook!

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 12:06 pm
by scuba steve 22
Grind back where you are welding and cold gal it, just like you said.but a trick i learnt when i was welding a lot of gal, is to drink plain milk,it helps keep the "gal fever "at bay. and use a mask for the fumes

cheers steve

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 12:24 pm
by 351ciofgrunt
Yeah I have also used a flap disc to sand away where I'll be welding.

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 12:32 pm
by Struth
If it is duragal RHS then it should weld fine, no need to clean first.

Just avoid breathing the fumes and drink milk regularly thru the job.

Cheers

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 12:38 pm
by MARKx4
Struth wrote:If it is duragal RHS then it should weld fine, no need to clean first.

Just avoid breathing the fumes and drink milk regularly thru the job.

Cheers
Will look into the duragal, i like the milk idea. I was thinking of masks, what type of mask do i need for gal fumes without going a resporator set up.

Mark.

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 1:06 pm
by Zookified
The box the masks come in will have on them what they are designed for. Go to your local safety shop or hardware and they should help you out.

Have heard that the fumes can cause some really serious health problems

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 2:17 pm
by sambo
Just avoid breathing the fumes and drink milk regularly thru the job.
What sort of milk do you recommend, full cream, skim or would Iced Coffee work as well.

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 2:53 pm
by oldmate
sambo wrote:
Just avoid breathing the fumes and drink milk regularly thru the job.
What sort of milk do you recommend, full cream, skim or would Iced Coffee work as well.

Breast is best.

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 4:14 pm
by cruzinnboozn
Excuse my ignorance, but what does the milk do??

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 6:45 pm
by 5inchgq
cruzinnboozn wrote:Excuse my ignorance, but what does the milk do??
Well I assume it is for the same reason that a lot of spray painters drink copious amounts of milk.

Gets the mucus production cranking from what I've heard.

Could be wrong though. ;)

Re: Welding galvanised steel.

Posted: Wed Jan 19, 2011 7:00 pm
by shanfab
why don't you use Perlin's for the floor beams instead of RHS . you can tech scew it all togeather and it's strong as hell .
I built one 12x7m and 1.5m high . used 75x75x3mm for the posts/stumps , and 6" Perlins for the floor beams .

Just make sure you use 14 gauge screw's .

this might be another option .

Re: Welding galvanised steel.

Posted: Thu Jan 20, 2011 11:42 am
by UPPY
what welding process are you useing? MMA(stick) GMAW(mig) FCAW(flux core wire). Forget the milk, prevention is better than a cure, use a P3 respirater. If you are useing MMA or FCAW you can also use a fan to blow the fumes away.

Re: Welding galvanised steel.

Posted: Thu Jan 20, 2011 12:01 pm
by Struth
cruzinnboozn wrote:Excuse my ignorance, but what does the milk do??
Something in milk is a natural antidote for gal poisoning. Doesn't mean it should preclude normal safety options such as a suitabkle mask, but it helps reduce the effects.

I have had mild gal poisoning heaps of times, makes you feel a bit dizzy and nauseous.

Got proper poisoning once, makes you really feverish and shivery, it's nasy poo.

Cheers

Re: Welding galvanised steel.

Posted: Thu Jan 20, 2011 2:50 pm
by MARKx4
UPPY wrote:what welding process are you useing? MMA(stick) GMAW(mig) FCAW(flux core wire). Forget the milk, prevention is better than a cure, use a P3 respirater. If you are useing MMA or FCAW you can also use a fan to blow the fumes away.
We will be using stick. The deck we will be building is about 14m x 18m and will be about 50mm above ground level so there is alot of welding to be done. Im going to look into respirater and defintly use fans aswell.


Can you hire respirater's?

Mark.

Re: Welding galvanised steel.

Posted: Thu Jan 20, 2011 3:19 pm
by brad 93hilux
Just buy the disposable ones, and as said use a fan...

Personally if it was me, I would prep surface with flap disc on grinder removing gal, use a fan and start welding.

The fumes would be minimal if prepped and fan would just blow away rest.

Brad

Re: Welding galvanised steel.

Posted: Thu Jan 20, 2011 6:49 pm
by 80's_delirious
5inchgq wrote:
cruzinnboozn wrote:Excuse my ignorance, but what does the milk do??
Well I assume it is for the same reason that a lot of spray painters drink copious amounts of milk.

Gets the mucus production cranking from what I've heard.

Could be wrong though. ;)
yep, it helps you cough up 'some' of the nasty shit you have inhaled. best thing is to avoid inhaling it in the first place.







oh yeah, skip the iced coffee, breast is definitely best :lol:

Re: Welding galvanised steel.

Posted: Thu Jan 20, 2011 6:58 pm
by Shadow
MARKx4 wrote:
UPPY wrote:what welding process are you useing? MMA(stick) GMAW(mig) FCAW(flux core wire). Forget the milk, prevention is better than a cure, use a P3 respirater. If you are useing MMA or FCAW you can also use a fan to blow the fumes away.
We will be using stick. The deck we will be building is about 14m x 18m and will be about 50mm above ground level so there is alot of welding to be done. Im going to look into respirater and defintly use fans aswell.


Can you hire respirater's?

Mark.
I weld duragal all the time and dont grind it or use a respirator. I try not to breath in the fumes though :oops: Welding hit dip gal i grind the gal back.

If i was you, I would be doing the whole thing out of C purlins. I have done hundreds of decks using C purlins. They are zincalume which is arguably better than gal. And with class3 tek screws screwing it all together you wont have to worry about corrosion. I use Stoddart Steel House Frames to supply all my purlins. But Strammit, etc all carry the stuff, and with the quantity your buying you can have them cut all the joists and bearers to length for you with a cold saw.

Also, if it is that close to the ground you need to make sure the ground has a descent amount of fall on it so water doesn't sit under there. consider putting down some roadbase or crusher dust, and compacting it, to help the water get away, and help stop rising damp.

50mm off the ground is far from ideal and i think your decking is going to rott out prematurely. If its at all possible consider a larger distance from the ground. Even excavating the area directly under the deck 200-300mm, and install a cloth lined agg pipe to carry the water out from under the deck, and to lower ground.

Re: Welding galvanised steel.

Posted: Thu Jan 20, 2011 8:01 pm
by RED60
Make your posts out of ordinary mild steel in the size you have shown and then get them hot dip galvanised... will give a longer lasting job and no gal fumes to contend with.... :cool: :cool:

Re: Welding galvanised steel.

Posted: Thu Jan 20, 2011 9:02 pm
by MARKx4
Shadow wrote:
MARKx4 wrote:
UPPY wrote:what welding process are you useing? MMA(stick) GMAW(mig) FCAW(flux core wire). Forget the milk, prevention is better than a cure, use a P3 respirater. If you are useing MMA or FCAW you can also use a fan to blow the fumes away.
We will be using stick. The deck we will be building is about 14m x 18m and will be about 50mm above ground level so there is alot of welding to be done. Im going to look into respirater and defintly use fans aswell.


Can you hire respirater's?

Mark.
I weld duragal all the time and dont grind it or use a respirator. I try not to breath in the fumes though :oops: Welding hit dip gal i grind the gal back.

If i was you, I would be doing the whole thing out of C purlins. I have done hundreds of decks using C purlins. They are zincalume which is arguably better than gal. And with class3 tek screws screwing it all together you wont have to worry about corrosion. I use Stoddart Steel House Frames to supply all my purlins. But Strammit, etc all carry the stuff, and with the quantity your buying you can have them cut all the joists and bearers to length for you with a cold saw.

Also, if it is that close to the ground you need to make sure the ground has a descent amount of fall on it so water doesn't sit under there. consider putting down some roadbase or crusher dust, and compacting it, to help the water get away, and help stop rising damp.

50mm off the ground is far from ideal and i think your decking is going to rott out prematurely. If its at all possible consider a larger distance from the ground. Even excavating the area directly under the deck 200-300mm, and install a cloth lined agg pipe to carry the water out from under the deck, and to lower ground.
I have never used C purlins so i dont know the process of using them, may look into it.

I was going to excavate down 200mm at the high point with a fall over the whole job too 300mm at the deep end. Im going to use concrete underlay, agg pipe and blue metal for drainage including piping the excess into the drainage pipe that runs out into the gutter.

Mark.

Re: Welding galvanised steel.

Posted: Sun Jan 23, 2011 3:42 pm
by ssfabricator
Milk does nothing to help your lungs
many years ago forjacs workers went on strike wanting the company to provide free milk for all the welders.
forjacs proved it to be bullshit and won
just wear a p3 mask
when i mig weld gal i use a flick method

Re: Welding galvanised steel.

Posted: Sun Jan 23, 2011 11:41 pm
by UPPY
MARKx4 wrote:
UPPY wrote:what welding process are you useing? MMA(stick) GMAW(mig) FCAW(flux core wire). Forget the milk, prevention is better than a cure, use a P3 respirater. If you are useing MMA or FCAW you can also use a fan to blow the fumes away.
We will be using stick. The deck we will be building is about 14m x 18m and will be about 50mm above ground level so there is alot of welding to be done. Im going to look into respirater and defintly use fans aswell.


Can you hire respirater's?

Mark.
Fark hireing a respirator, just buy one (it's your lungs not mine) If you are useing MMA you are about to learn some invaluable lesons, IE, you will get alot of slag inclusion and a shit load of spatter the best way to weld gal is to back step the arc, and keep an eye on the weld pool to understand what is happening, as some people have already mentioned bolt as much as you can, your arms will thank you later!

Re: Welding galvanised steel.

Posted: Mon Jan 24, 2011 6:21 am
by V8Patrol
shanfab wrote:why don't you use Perlin's for the floor beams instead of RHS . you can tech scew it all togeather and it's strong as hell .
I built one 12x7m and 1.5m high . used 75x75x3mm for the posts/stumps , and 6" Perlins for the floor beams .

Just make sure you use 14 gauge screw's .

this might be another option .

I agree 100% :armsup:

1/ SIGNIFICANTLY faster construction

2/ Forget the welder and the slowness of it all + NO FUMES

3/ a simple unscrew and adjustments ( levels) are dead set easy to do

4/ NO RUST issues with unpainted welds & 'some' so-called duragal is NOT coated internally

5/ no cavities = easy inspection and cleaning



:armsup:

Re: Welding galvanised steel.

Posted: Mon Jan 24, 2011 7:51 am
by MARKx4
V8Patrol wrote:
shanfab wrote:why don't you use Perlin's for the floor beams instead of RHS . you can tech scew it all togeather and it's strong as hell .
I built one 12x7m and 1.5m high . used 75x75x3mm for the posts/stumps , and 6" Perlins for the floor beams .

Just make sure you use 14 gauge screw's .

this might be another option .

I agree 100% :armsup:

1/ SIGNIFICANTLY faster construction

2/ Forget the welder and the slowness of it all + NO FUMES

3/ a simple unscrew and adjustments ( levels) are dead set easy to do

4/ NO RUST issues with unpainted welds & 'some' so-called duragal is NOT coated internally

5/ no cavities = easy inspection and cleaning



:armsup:
Definetly going to have to look in to it. Does any one have any links to a supplier and can PM me, so i can pics or ideas emailed.

Re: Welding galvanised steel.

Posted: Mon Jan 24, 2011 9:13 am
by Struth
The only advantage I can see with purlins is that they are easier to use, no real skills required.

For a permanent structure better to weld it all up properly, take your time and do the job right, it's not like it wont be there for a long time afterwards.

Cheers

Re: Welding galvanised steel.

Posted: Mon Jan 24, 2011 9:32 am
by MARKx4
Struth wrote:The only advantage I can see with purlins is that they are easier to use, no real skills required.

For a permanent structure better to weld it all up properly, take your time and do the job right, it's not like it wont be there for a long time afterwards.

Cheers
I just done some research on perlins, it is a easier product to use and will be strong enenough to stand the test of time aswell. I do like the idea of welding but if i use perlins i dont have to get a mate of mine to spend a couple of days welding for me and i can do it all my self.

I dont like the idea of holding it all together with tek screws though. I may use tek screws and bolt it after if i use pelins.

I will quote up cost of both and make my mind up after that.

Mark.

Re: Welding galvanised steel.

Posted: Mon Jan 24, 2011 9:03 pm
by pongo
the fumes from welding gal contain arsnic. My old man died from a cancer caused mainly from welding gal for years at work without any breathing protection.

Be very carefull. thesedays i always use a fan to blow any fumes away when im welding anything.

Goodluck

Re: Welding galvanised steel.

Posted: Tue Jan 25, 2011 6:54 am
by V8Patrol
MARKx4 wrote:I dont like the idea of holding it all together with tek screws though. I may use tek screws and bolt it after if i use pelins..

Kit sheds are largely screwed together these days....

and are standing the time test so far


if a shed can stay up with just screws then I seriously doubt that a deck will make a screws life any harder

;)

Re: Welding galvanised steel.

Posted: Tue Jan 25, 2011 5:19 pm
by Mick.
brad 93hilux wrote:Just buy the disposable ones, and as said use a fan...

Personally if it was me, I would prep surface with flap disc on grinder removing gal, use a fan and start welding.

The fumes would be minimal if prepped and fan would just blow away rest.

Brad
That's what I'd be doing to. It's really the only safe way to do it.

I weld gal & dura gal all day every day and I've had gal poising where I've felt like I'm having a severe asthma attack and can feel like crap for a day or 2 after it. As mentioned above it's not a nice feeling.

I now wear an air fed welding mask when i'm welding it. You just have to remember not to fart when your wearing it. :rofl:

Cheers Mick.

Re: Welding galvanised steel.

Posted: Thu Jan 27, 2011 6:51 am
by BJMorgo
Duragal is only around a 100 grams/square metre zinc (one side only) - purlins are Z350 or Z450, which is about 175 or 225 per side. You really need to paint the Duragal for it to last. Tubes have better stiffness than purlins. The old Palmer/Smorgon mill in Brisbane (now also Onesteel)makes "Supagal" which is galvanized both sides, but is still only a light coating though.

As someone said you don't need to weld it - steel house frames are all Tek screwed and bolted together and they work very well. The people selling the purlins and tubes will have span tables and advice on how to connect it all together. If you must weld it remove the zinc locally and re-spray with cold gal so there's less fumes to worry about and so it welds properly.