Steel Prep for ERW Square Semi-Bright Tube

[BoatBuilderDave]

This does not have mill scale like hot rolled steel. It just seems to have a light coating of oil. What's the best (easiest) way to prep this for welding?

I've been cleaning it with a rag, and using a flap disk on a grinder to make the last inch or so shiny.

Is this overkill for mig welding? Or about right?

Also, for painting afterwards, do I need to make it all shiny, or just clean it with ???

 

[J.B. Welding]

Hi,
It sounds like you are doing right, a wipe with a rag and maybe a bit of de-greaser to get the oil away. No need to grind it too much, just around where the weld goes is fine. A cup brush is ideal for paint prep., the important thing is clean the welds well and get rid of the oil and any oxide, shiny is good though!

 

[Wendelspanswick]

Hi,
It sounds like you are doing right, a wipe with a rag and maybe a bit of de-greaser to get the oil away. No need to grind it too much, just around where the weld goes is fine. A cup brush is ideal for paint prep., the important thing is clean the welds well and get rid of the oil and any oxide, shiny is good though!

Agree but not polished otherwise the primer will struggle to adhere unless you use an etch or epoxy.

 

[BoatBuilderDave]

The cup brush with the fine hairs I'm guessing? The one with the big twisted wires seems overkill...

Hi,
It sounds like you are doing right, a wipe with a rag and maybe a bit of de-greaser to get the oil away. No need to grind it too much, just around where the weld goes is fine. A cup brush is ideal for paint prep., the important thing is clean the welds well and get rid of the oil and any oxide, shiny is good though!

 

[Bill Edwards]

Yep, they're more suited to heavy rust removal.

I'd be using brake/clutch/parts cleaner - buy it in a 5l can and it isn't expensive, and keep it in a spray bottle. It's flammable so don't have the bottle too close to welding or grinding but it gets rid of oil and grease very well and is great for welding or painting.

http://www.ebay.co.uk/itm/BR606-BRA...707?pt=LH_DefaultDomain_3&hash=item3a81a3b4e3

Whatever you do, prior to painting you'll need some kind of solvent to clean the metal.

 

[the snooper]

Yep, they're more suited to heavy rust removal.

I'd be using brake/clutch/parts cleaner - buy it in a 5l can and it isn't expensive, and keep it in a spray bottle. It's flammable so don't have the bottle too close to welding or grinding but it gets rid of oil and grease very well and is great for welding or painting.

Whatever you do, prior to painting you'll need some kind of solvent to clean the metal.

im sure there was a thread on here before regarding brake cleaner giving off dangerous fumes when used in conjunction with welding

EDIT just looked it up and it seems it was nonsense

 

[Bill Edwards]

im sure there was a thread on here before regarding brake cleaner giving off dangerous fumes when used in conjunction with welding

EDIT just looked it up and it seems it was nonsense

Ah, that gets mentioned every time I suggest brake cleaner!
I always suggest it as it is so effective.
Then I nearly always have to point out that the stuff bought in this part of the world doesn't contain the dangerous chemical that caused people to worry, I think you're the first one to have looked it up before I needed to reply!

 

[the snooper]

Ah, that gets mentioned every time I suggest brake cleaner!
I always suggest it as it is so effective.
Then I nearly always have to point out that the stuff bought in this part of the world doesn't contain the dangerous chemical that caused people to worry, I think you're the first one to have looked it up before I needed to reply!

it just popped into my mind that id seen it, so a quick post just in case and off to look it up

 

[BoatBuilderDave]

Thanks guys. For now, it's just a welding cart, but then I want to rebuild this in lighter steel (16 gauge, not 14 gauge)
This was done with an arc welder. Trying that in 16 gauge would not be fun.

Then I want to build one of these - atomiczombie.com

-

 

[chevy2]

Erw tube and box needs no prep for arc, mig or tig welding,
just make sure its clean, ie remove the oil coating it comes with.

 

[chunkolini]

Like the short wheelbase recumbent.
Where did you get the seat from, I am debating building a tandem recumbent.
I have a long wheelbase jobbie, and have always fancied a tandem.

 

[Gareth0123]

I am currently building an adapted version of the AZ Warrior Tadpole Trike with rear suspension and a (Kayak type) sail. My DIL to be (who is Dutch) has challenged me to pedal and sail it across Holland from Rotterdam to Nijmegen in only one day.

 

[J.B. Welding]

Erw tube and box needs no prep for arc, mig or tig welding,
just make sure its clean, ie remove the oil coating it comes with.

I would agree there, but it depends of course on how long it has been sitting around and how oily it is. The oil can stink the place up a bit so its removal from at least the outside of the box section helps there. A rub with sand paper is as good as anything really, or stiff wire wheel, and paint thinners or white spirit are a cheap form of pre paint prepping.. As I'm not a mechanic brake cleaner is wasted on me-I guess lots of people will have all sorts of solvent degreaser kicking around but I prefer thinners as it is obviously suited to painting applications.

 

[BoatBuilderDave]

The seat is two sheets of 6mm ply, bent over a form and glued. Add a yoga mat, cut to size and some vinyl for a cover. A Google of plywood recumbent seat should find the plans. There's several copies out there.

 

[BoatBuilderDave]

The plans for the seat... https://archive.org/details/AnatomicSeatRecumbentBikeSeatPlans