Thread: Snapped Bolts, Poor Mans Oxy?

ive found a cheapie TIG set up hopefully just waiting to find out if the old stick welders are DC power if so ill jerry rig it up like the guy on the everlast video on youtube said to and have a cheap TIG machine for under $100

Originally Posted by jhovel

If using MIG, I found it best to drill a hole into the bolt/stud, then fill that up with weld. As it shrinks, it reduces the bolt/stud diameter slightly. Then weld on a pimple or nut. Found this worked after several other attempts just welding to the end had failed and broke off.

i have a whole 10L pale of nuts and bolts ive stripped from various engines over the years so i was just going thru the bucket using what i had on hand, some of the nuts are 6-7mm tall so it was a little hard to aim the MIG wire down into the middle of the nut as these are actually 6mm snapped bolts so tiny bolts, how will i get the weld so deep into a drilled snapped bolt?

Originally Posted by gazza2009au

ive found a cheapie TIG set up hopefully just waiting to find out if the old stick welders are DC power if so ill jerry rig it up like the guy on the everlast video on youtube said to and have a cheap TIG machine for under $100

Most transformer arc welders are AC, although you can still TIG with AC (it's just not ideal on steel, ok on aluminium).

I actually bought an old TransTig AC DC tig for $100

Originally Posted by Vernonv

Most transformer arc welders are AC, although you can still TIG with AC (it's just not ideal on steel, ok on aluminium).

I actually bought an old TransTig AC DC tig for $100

yeah i found that in a search about an hour ago that the small arc welders are AC what a shame well there goes that idea and the BOC TIG just jumped almost $100 in price on ebay so i wont be buying that

just picked up some steel nuts and nice size washers both slightly bigger than my snapped bolts, these washers will allow me to weld the nut to the washer on the inside and outside so fingers crossed it works, raining now so will work on it tomorrrow

if that fails i picked up some 2mm cobalt drill bits ill try drill it out

Originally Posted by gazza2009au

yeah i found that in a search about an hour ago that the small arc welders are AC what a shame well there goes that idea and the BOC TIG just jumped almost $100 in price on ebay so i wont be buying that

just picked up some steel nuts and nice size washers both slightly bigger than my snapped bolts, these washers will allow me to weld the nut to the washer on the inside and outside so fingers crossed it works, raining now so will work on it tomorrrow

if that fails i picked up some 2mm cobalt drill bits ill try drill it out

What ever you do, DON'T use ezyouts, as they expand the bolt thread, so that it is tighter than the original. I'd be inclined to make a tool with a hardened collar and 2mm hole on top, mounted onto a 6mm slotted bar, with a 6mm hole in the bottom to locate over the stub of bolt, that can be set up on a bolt hole to drill central on the sheared bolt. The reason for the slotted bar, is so that it can be bolted down, using existing holes and be rigid so that it won't move. As you repair a lot of motors with this problem, the time taken to make the tool will not be wasted.
Once all the holes have been drilled through centrally, they can be drilled out to 4.9 or a bit under and the tread can then be picked out, CRC/WD40 can be put down the hole the help ease the corrosion, or a fine pointed micro torch to heat the wire red hot, to break the seal.
PM me if you'd like a drawing to help explain the tool.
Regards
Kryn

so i tried drilling out the bolts the drill bit wondered off center even tho i used a punch

whats the next step in salvaging this job? i didnt drill the holes perfectly strait and a couple of starts have drifted off center how do i restart these holes?

i hope there is a fix and someone has experienced the same problem as me before and know how to deal with this situation

Put a (soft) steel pin in and try again. Something like a nail should work (you may have to juggle hole sizes to get a good fit + use loctite to glue it in). Really for doing this sort of thing a drill press is the go - that way you can clamp up the part once you have position and be fairly safe that things won't move.

Michael

ok finishing up this thread seeing its in the welding forum, i just made up a bodgey jig and clamped it in place and it works brilliantly altho im probably better off making one from SS as the top hole is slowly egg shaping

heres what i done with the hole i screwed up, used the jig and it centred the hole

i put two pieces of flat aluminium 6mm under each side of the 20x20 steel tube so i can see and aim the drill bit to the center of the bolt

Originally Posted by gazza2009au

ok finishing up this thread seeing its in the welding forum, i just made up a bodgey jig and clamped it in place and it works brilliantly altho im probably better off making one from SS as the top hole is slowly egg shaping

heres what i done with the hole i screwed up, used the jig and it centred the hole

i put two pieces of flat aluminium 6mm under each side of the 20x20 steel tube so i can see and aim the drill bit to the center of the bolt

Hi gazza, that is more or less what I was describing in an earlier thread. When you get a chance make a proper one so that it is there for next time.
Kryn

Originally Posted by KBs PensNmore

Hi gazza, that is more or less what I was describing in an earlier thread. When you get a chance make a proper one so that it is there for next time.
Kryn

yeah when i get a chance to order the steel ill goto jaycar and grab one of these too so i can make a few different sizes http://www.jaycar.com.au/Tools-%26-S...Stand/p/TD2463

found it was best in my interest to buy another TIG welder so found this one on ebay for a couple hundred bucks i bought it from a young guy who couldnt get the hang of TIG welding, its a REPCO branded ARC welder with the optional TIG kit with a full bottle of argon

do u think it'll be worth a shot at heating and cooling the snapped and drilled bolts before TIG welding a nut onto each bolt than attempt the removal or do u think just go a head and heli coil them as im half way there? altho the holes are around half a millimeter of center

Originally Posted by gazza2009au

found it was best in my interest to buy another TIG welder so found this one on ebay for a couple hundred bucks i bought it from a young guy who couldnt get the hang of TIG welding, its a REPCO branded ARC welder with the optional TIG kit with a full bottle of argon

do u think it'll be worth a shot at heating and cooling the snapped and drilled bolts before TIG welding a nut onto each bolt than attempt the removal or do u think just go a head and heli coil them as im half way there? altho the holes are around half a millimeter of center

I'd definitely have a go at heating and cooling although I am more of a fan of building up a big enough stub to grab with vice grips rather than welding nuts on. Probably more a personal preference thing though.
I like to think of removing snapped bolts/studs as a staged response. You start with the least invasive, safest and simplest option and work up to the most invasive, riskiest and hardest option. For the beginner, drilling stainless bolts/studs is not a simple exercise and one that I rate as risky for all the reasons you are experiencing. Not to say it can't be done, but there are a few tricks and skills that make the difference between success and a failure that is hard to repair.
I suggest that you practice building up a stub on a few scrap bolts threaded into nuts - even try a few recessed into the nut, before you commence operations in anger on more critical jobs so you can get the hang of the power settings required and the general process. Much easier to grab another nut and bolt than to try and recover an outboard block or leg.

Karl i feel very comfortable TIG welding i feel at home where as ARC and MIG welding im not so comforable as TIG is at my pace

i just done some TIG welding on the bolts i welded 2 drilled bolts and 1 not drilled, the two which i had drilled came free one was removed and im working on the other one, the one that wasnt drilled just snapped again

im also getting some contamination in my welds they are bubbling as im heating up the bolts i think it could be the WD40 down the hole or it could be oxygen coming up thru the drilled hole but the molten metal is bubbling and bursting but still im able to get an ok weld down

getting use to the scratch start is tricky on a 6mm bolt u cant really scratch it but once the arc starts im off and running

heres some pics of the first bolt i welded and removed it

my initial "guess" on the amp setting was spot on at 25amps

the third snapped bolt i just welded a washer to the bolt and used multigrips to free it up i think i need to drop back to around 15amps and heat the bolt more it freed up i can spin the bolt about one full turn but its tight

forgot to add my new TIG welder came with a free full disposable gas bottle i got around 1 hour welding out of it maybe just over 1 hour

i cut off the disposable cylinder regulator and tried attaching my argon regulator (i have two) but couldnt make a propper connection so i need to go order the right connection before i can do more welding, cant bloody wait

Glad to hear it's working out for you.
25A seems low, but if it's working then run with that. Scratch start is an added degree of difficulty, but you sound like you're on top of it. With the potential crud you are dealing with, aluminium oxide, oil, rust etc, porosity is not surprising.
Tig really is a nice process isn't it.