gate

[aidank]

brother wants me to make a gate for him, about 8ft wide 6ft tall, to block off the footpath at the side of his house

going to use box iron so prob 40x40x3mm for outside and next size down 30x30x3mm for the up down bars, prob space them about 6inch apart, stop intruders going through it, weld on a few spikes at the top and a few decorations here and there make it look good

when welded going to send the whole lot to be galvanised

going to buy one of these 2axis clamps or maybe a 3axis to make sure everything fits up right be handy anyway for other jobs

http://store.cyberweld.com/sthawecl3ax.html

anyone use one are they worth it?, is the 3axis functionality a benefit or a curse, what should I be paying, prices seem to vary massively?

wonder can you get one where you remove the 3axis functionality and rebolt it up when you need it?

also often see gates similar to what I want to make with a hole in each of the up and down bars just above where its welded at the bottom, whats the purpose of this hole, allow air to circulate, seems to me like it would simply allow rainwater get in and the gate to rot from the inside out

 

[Thebuttrussler]

The holes are to stop it blowing apart, when you hot dip galv, it's at around 400-500 degrees C. so as you dip you let expanding hot air inside the structure to escape. Holes should be drilled opposites and top and bottom of every sealed section.
There is probably a diagram on the web some where, galvanising design or something like that.
ATB

 

[Country Joe]

anyone use one are they worth it?, is the 3axis functionality a benefit or a curse, what should I be paying, prices seem to vary massively?

I've got some 2 axis ones, huge heavy things they are too.
Not seen a 3 axis one before, though.
Made by SIP, as I remember!
All the Best,
CJ

 

[aidank]

The holes are to stop it blowing apart, when you hot dip galv, it's at around 400-500 degrees C. so as you dip you let expanding hot air inside the structure to escape. Holes should be drilled opposites and top and bottom of every sealed section.
There is probably a diagram on the web some where, galvanising design or something like that.
ATB

Interesting never knew that, whats the right way seal them up again after, stop the water getting in

 

[brightspark]

Interesting never knew that, whats the right way seal them up again after, stop the water getting in

they wont need sealing because there galvanised inside

 

[aidank]

they wont need sealing because there galvanised inside

so if i make a 6mm hole top and bottom in my 30mm box section ~6ft long it will allow the inside to be coated with galvanised

 

[brightspark]

so if i make a 6mm hole top and bottom in my 30mm box section ~6ft long it will allow the inside to be coated with galvanised

yes

 

[Thebuttrussler]

Interesting never knew that, whats the right way seal them up again after, stop the water getting in

No need as the inside is galvanised too, and any water will drain from the bottom hole
ATB

 

[aidank]

so whats the galvanising process

1 sandblast
2 chemical treat
3 dip in zinc or should this be, allow to soak for 10-15mins
4 remove

All I know is that its important to ensure all slag is removed from welds as this causes the zinc not to stick v well

 

[Wozzaaah]

so if i make a 6mm hole top and bottom in my 30mm box section ~6ft long it will allow the inside to be coated with galvanised

No, you'll need holes at least 10mm or the molten zinc won't flow through the section and drain out which is one of the main purposes of them.
If you take things for galving and they're not properly vented they'll give you two options, you either take it away, vent it yourself and bring it back or they will do it for you....probably badly....and charge you per hole.

 

[Wozzaaah]

so whats the galvanising process

1 sandblast
2 chemical treat
3 dip in zinc or should this be, allow to soak for 10-15mins
4 remove

All I know is that its important to ensure all slag is removed from welds as this causes the zinc not to stick v well

Make items, clean off spatter, take them to be galved!
They will acid dip them to remove any millscale and rust then dip them in the zinc....that's pretty much it.

 

[KemppiFrog]

I prefer to drill the vent holes in the exterior frame, where I am going to weld the infill tubes, the vent the frame at the top and bottom corners on the outside faces. No visible holes.
Quite a lot of mine are with round tube set in holes in the outer frame. Same result.
KF

 

[aidank]

I prefer to drill the vent holes in the exterior frame, where I am going to weld the infill tubes, the vent the frame at the top and bottom corners on the outside faces. No visible holes.
Quite a lot of mine are with round tube set in holes in the outer frame. Same result.
KF

thats the plan I had in mind

 

[aidank]

No, you'll need holes at least 10mm or the molten zinc won't flow through the section and drain out which is one of the main purposes of them.
If you take things for galving and they're not properly vented they'll give you two options, you either take it away, vent it yourself and bring it back or they will do it for you....probably badly....and charge you per hole.

do I need to go 10mm?

 

[pedrobedro]

The item can be weighed before then after to se how much galv it has retained and charged for. If the holes are not big enough they can skin over and retain the zinc inside the sections making it very heavy and expensive.

 

[Hitch]

I prefer to drill the vent holes in the exterior frame, where I am going to weld the infill tubes, the vent the frame at the top and bottom corners on the outside faces. No visible holes.
Quite a lot of mine are with round tube set in holes in the outer frame. Same result.
KF

All well and good, but sometimes they can be a bit funny about internally vented items, as they cant see the holes, whos to say its been done adequately.
They ask for pictures to prove that it has been done sometimes.

Dont let them vent it unless you are deperate, they will most likely blow holes in it with the gas in the worst place possible

 

[Welderpaul]

Ours will accept internally vented gear as long as you sign their disclaimer.
There are loads of photos on their office wall of box section and tubes that have blown open because they have not been vented properly. Shocking show they blow, and shower molton zinc all over the place. I'll try get a picture of them next time i'm in.

 

[KemppiFrog]

All well and good, but sometimes they can be a bit funny about internally vented items, as they cant see the holes, whos to say its been done adequately.
They ask for pictures to prove that it has been done sometimes.

Dont let them vent it unless you are deperate, they will most likely blow holes in it with the gas in the worst place possible

After the first time when they asked, not had any questions.
And, they charge by weight of the steel. With a fudge factor depending on the complexity of the design. Since they are the only game in the dept. One has to accept it.