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Main Forums => The Roundtable => Topic started by: zahc on January 06, 2020, 12:57:07 AM

Title: Gas welding thick stuff
Post by: zahc on January 06, 2020, 12:57:07 AM
I want to weld a collet block to a QC lathe tool holder. So both pieces are like 1 inch thick. I gas weld thin metal and tubing but never things that thick. Will it work?
Title: Re: Gas welding thick stuff
Post by: French G. on January 06, 2020, 01:05:05 AM
Got any other processes available? It can be done, but going to dump a ton of heat in there. Any pics? Intended use? Doesn't sound like it needs to hold the world on, so just a bit of bevel and a lighter weld?
Title: Re: Gas welding thick stuff
Post by: zahc on January 06, 2020, 01:15:51 AM
I want the collet block on my lathe toolpost so I can clamp thin tubing. Forces will not be tremendous. I just want it to be rigid so I thought I would weld it instead of drilling and tapping holes to bolt it on. Usually in this situation I end up laying down a big brass bead, because brazing is so easy.

You just reminded me I have an $80 chinese 120V stick welder, but that thing is so hard to run a bead with and it trips the breaker about every inch or so.
Title: Re: Gas welding thick stuff
Post by: Hawkmoon on January 06, 2020, 02:01:33 AM
I've only done a little bit of wire welding and a little bit of stick welding but, for chunks of metal that thick I think you'll be better off using the stick welder. What kind of circuit are you running it on -- 15A or 20A?
Title: Re: Gas welding thick stuff
Post by: dogmush on January 06, 2020, 02:28:04 AM
I would probably try to silver solder that.

Or machine a ledge in the collet block and just bolt it in the tool holder like normal.

But really, silver solder is probably the easy answer.
Title: Re: Gas welding thick stuff
Post by: dogmush on January 06, 2020, 07:50:04 AM
There's also this:

AXA 5C collet holder: https://www.ebay.com/p/1501591033

Aloris makes BXA size as well, if that's your thing.
Title: Re: Gas welding thick stuff
Post by: charby on January 06, 2020, 08:19:55 AM
You're probably going to spend more money on bigger tips and a rosebud, then just having a local welder or machine shop weld it for you. 1" is a lot to weld with most home shops. I've oxy-acetylene welded thicker iron but you burn a lot of fuel.
Title: Re: Gas welding thick stuff
Post by: zahc on January 06, 2020, 09:19:18 AM
There's also this:

AXA 5C collet holder: https://www.ebay.com/p/1501591033

Aloris makes BXA size as well, if that's your thing.

I admit I didn't know that I could but one off the shelf. But since they cost $150 and I can build it with things I already have I'm still going to try.

The fit together flat, so I could solder them. I have several types of silver solder, including this:

https://ads.midwayusa.com/product/1007081353


I could probably just lie the parts on top each other with some solder in between and set them on the stove.
Title: Re: Gas welding thick stuff
Post by: French G. on January 06, 2020, 09:52:10 AM
I've tacked up stuff similar for a lathe and got by with 3 1/4" tacks.
Title: Re: Gas welding thick stuff
Post by: Brad Johnson on January 06, 2020, 10:45:26 AM
Have pics?

Like several have said, gas welding something with that much mass is gonna take a metric buttload of heat. Even brazing will take more than you expect. Stick is your best bet, but you said your welder is tripping the breaker. Will it run long enough for you to tack it solid, or at least solid enough that it would survive a trip to the welding shop for a finish weld?

Brad
Title: Re: Gas welding thick stuff
Post by: zahc on January 06, 2020, 10:51:53 AM
Collet block:

5C-CB 5C Collet Block Set - Hex Collet Block, Square Collet Block and Collet Closer by 5C Tooling https://www.amazon.com/dp/B0186MD7L2/ref=cm_sw_r_cp_apa_i_Oz1eEbYRKFJQT

Tool holder:

CXA #2 QUICK CHANGE TURNING FACING & BORING TOOL POST HOLDER 250-302 https://www.amazon.com/dp/B01MQQINEL/ref=cm_sw_r_cp_apa_i_JA1eEbBR045YF


I could weld or bolt a strip onto the collet block to clamp it into the tool holder and avoid ruining a tool holder. But for all the more the tool holders cost I figured I would just bolt or weld it to the holder to be more rigid.

They're both ground flat so I'm interested in the idea of sweating them together. I would need a forge to get them both hot enough to braze together with brass but I could probably silver solder them with a propane stove burner.

My stick welder trips a 20A breaker every inch or two. That's not the biggest problem; it's more the sheer frustration of getting an arc started. It's just a dumb transformer buzzbox and with only 120V available it takes ninja skills to use it. I've been going to wire up a pigtail so I can use it on my 4-wire 240v brewing circuit, still with 120V, but with a 30A breaker. However, at that point I wonder if I should just wire it to 240v and reap the benefit of the higher voltage and probably a lot less current. Paradoxically, wiring it to higher voltage might be easier on the thing than 120V, and might make it easier to weld with.

Title: Re: Gas welding thick stuff
Post by: Boomhauer on January 06, 2020, 10:00:52 PM
There is undoubtably a way to do it but I’d just find someone with a more suitable welding process to do it instead

Title: Re: Gas welding thick stuff
Post by: Jim147 on January 06, 2020, 10:11:38 PM
Is this cast iron?
Title: Re: Gas welding thick stuff
Post by: dogmush on January 07, 2020, 01:35:17 AM
Is this cast iron?

No.  They tend to be ground, hardened steel.  If you buy the Chinese ones: for some values of "hardened".
Title: Re: Gas welding thick stuff
Post by: tokugawa on January 07, 2020, 02:28:06 AM
There are  critical surfaces to warp on this- the dovetail on the toolholder, the interior 5c taper of the collet block etc.
 
 This is to hold tubing so a cutter in the lathe spindle can work on it?

 
Title: Re: Gas welding thick stuff
Post by: zahc on January 17, 2020, 09:25:07 AM
What I ended up doing is upgrading my welder from the very bottom of the barrel to the dregs of the barrel. I bought a Deka inverter welder. It's about the size of a lunch box, weighs like 6 pounds, runs on 220 or 110 with a cord adapter, and I'm blown away by how well it runs 3/32 7018. $130. Technology is an amazing thing.

So yeah instead of buying a collet holder for $150, I'm in it for like $170 but hey I have a new welder.
Title: Re: Gas welding thick stuff
Post by: RoadKingLarry on January 17, 2020, 10:28:12 AM
There is no reason to spend $200 on a part when you can spend $1000 on the tools to make it you self.
Title: Re: Gas welding thick stuff
Post by: MillCreek on January 17, 2020, 11:20:06 AM
There is no reason to spend $200 on a part when you can spend $1000 on the tools to make it you self.

I say a similar thing about the wife's craft-making: she spends hundreds of dollars on supplies and equipment to make a $ 7 card.