quick exhaust from emt condiuit

[Sidewinder Jerry]

What method of welding did you use?

 

[el diablo guapo]

this is a hobby for me, but the fabrication pics are inspiring, i particularly the awesome expansion chamber fabs!

i just have a small flux core setup, but when i dial it in and move steadilly it can do a great job

i use a fan to blow away the fumes in the situation under discussion, and this exposure time is short.

bikes are actually tricky to weld - thinwall and round= challenging, so cleaning it up just makes it easier

 

[Sidewinder Jerry]

If you plan to do more builds please develop safe working procedures with galvanized tubing. Maybe instead of a fan, duck tape a large funnel to a shop vac so that it sucks the fumes away. Weld outside, get a respirator and chemically clean the pipe. By chemically removing it the pipe will be easier to weld. EMT is like welding with 18 gauge sheet metal where IMC is like using 14 gauge. Headsmess used 14 gauge on the exhausts he made. He said 0.7-0.9 but I know he ment 0.07-0.09. We're all human and sometimes make simple mistakes.

Your bike looks really good. Putting cool exhaust pipes and/or expansion chamber on them is going to cause others to want similar things put on their bikes. Thus exposing you more often to galvanized poisoning.

 

[HeadSmess]

If you plan to do more builds please develop safe working procedures with galvanized tubing. Maybe instead of a fan, duck tape a large funnel to a shop vac so that it sucks the fumes away. Weld outside, get a respirator and chemically clean the pipe. By chemically removing it the pipe will be easier to weld. EMT is like welding with 18 gauge sheet metal where IMC is like using 14 gauge. Headmess used 14 gauge on the exhausts he made. He said 0.7-0.9 but I know he ment 0.07-0.09. We're all human and sometimes make simple mistakes.

Your bike looks really good. Putting cool exhaust pipes and/or expansion chamber on them is going to cause others to want similar things put on their bikes. Thus exposing you more often to galvanized poisoning.

no, 0.7 to 0.9 MM like trying to weld paper. well, ok... cereal boxes. if the fit up isnt perfect, you need filler. or blow holes everywhere. chillers would be nice but im lazy (needle nose vice grips with curved, pivoted lumps of brass to soak up the heat AND hold the things where i want em! luxury!)

.07 in thou...um... lemme see now... almost 2mm. cant even roll it once its at 1.6!


not sure what that is in AWG, but im guessing a 24 guage or so...

youll notice the one on the BMX cruiser frame is made in galvanised. pretty sure i ground back a bit though tig has the advantage of not spitting on gal.

my safety tip when welding....WEAR EARPLUGS. nose plugs would help but i value my hearing more than my sense of smell... earplugs just cus earmuffs dont fit under the helmet too easily

you can live with a few burns here and there, even... there! just not down the earholes, thanks.

 

[HeadSmess]

other thing i found when forced to do gal work...

the reason it spits is this... zinc melts at around 300, vaporises at 600 or so (celcius). its a very volatile metal when liquid! hence the fumes.

steel, meanwhile...its melting at around 1200 celcius... with tig....you melt the steel, and the zinc just boils away and disappears.

with mig or stick...the steel filler is also melting... and just covers the zinc.

zinc boils, is confined...the steels still soft and liquid...zinc just blasts it out the way

there was a technique to mig welding over gal to stop the spitting. cant remember how i do it, but i remember as soon as i pick up a gun... bit of fiddling with feeds, speeds, current and which direction travelled...


when you get good spray transfer, spitting becomes almost nonexistant anyway.

still. dont weld gal!

 

[Sidewinder Jerry]

Sorry about that originally I think I asked what gauge you used. 0.7mm is around 23 gauge and 0.9 mm is around 20 gauge. That is some thin stuff to be working with. I feel the video on how to chemically clean off galvanized conduit offers the best option for working with it. Even then I'd wear a respirator and use a vacuum system to get any possible fumes away from me.

 

[Sidewinder Jerry]

I thought you were using 14-13 gauge sheet metal. That would be around 1.9-2.3 mm thick.

 

[HeadSmess]

tried using 0.5 in stainless once, but i found my POS tig doesnt go that low! even when dumping half the current through a big fat resistor, it just melts, surface tension makes it blob. theres a stinking big hole...and stainless doesnt like being overheated! really needs to be welded in a cabinet, has to be shielded on the rear too.


so 0.7 is my limit in mild even. stainless needs less current than mild.


not too mention you CANT SHAKE when the arc is held at less than 1mm... (ie, stop worrying about what youre doing and think of ducks or something) and the rod always tries blobbing up and dips your tip for you. read...swear, regrind electrode, grind off blob.... when the fit is good, theres no rod needed. just start the arc and zip round, quick!

alloy, i havent gotten below 2mm yet without making a mess

usually make a mess anyway with alloy


one day i might be able to afford a nice $2000+ miller or lincoln...

 

[Sidewinder Jerry]

Ok EMT 1/2" wall thickness is around 1.08 mm. IMC 1/2" is around 1.8 mm. Rigid 1/2" is around 2.66 mm.

 

[HeadSmess]

suddenly, while sorting through my pics, i was reminded of this thread!

i found a pic of a tig weld i did.

on rusty steel mind you.

overhead. ie, up. over my head. just cus i was lazy and didnt want to turn the thing around the practise is good.




and one that i cant really remember...




now, im not claiming to be an expert, im not officially trained as such, but i think i know what a tig welder is and how to use one...


do an image search on those pics and they should only appear in one other place. and guess what the users name will be...
(edit...all i could find was this being visually similar!!

awww )

anyway. back to what i was doing...