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Used and abused Robin bench vise
- Thread starter DPittman
- Start date
DPittman
Ultra Member
Okay it looks like I'm going to be successful in getting all broken jaw bolts out and rethreaded so now I am ready for some welding advise!
I have no TIG, only small MIG, AC/DC stick and acetylene/oxygen welding capabilities. I expect stick machine with some sort of nickel electrode is what I should do?
I wondering about the large amount of build up i will need to do it need to be over 1" thick in areas and both above and below the jaw needs material replaced that I will then plan on machining.
I understand preheating, peening and slow cooling will be important.
I have no TIG, only small MIG, AC/DC stick and acetylene/oxygen welding capabilities. I expect stick machine with some sort of nickel electrode is what I should do?
I wondering about the large amount of build up i will need to do it need to be over 1" thick in areas and both above and below the jaw needs material replaced that I will then plan on machining.
I understand preheating, peening and slow cooling will be important.
DPittman
Ultra Member
You mean like weld pieces on? The one corner would be possible maybe.
If it were me, I'd clean it very well, get any grease and oil off, grind out the areas to be welded, and the cook it in an old BBQ for and hour as hot as it'll go. Have a bunch of cool bricks handy to rest your arms on. Open BBQ , shut off heat and build it up with weld right on the BBQ. After welding turn the heat on until its as hot as it'll go, let it simmer for a bit then let it slowly cool. The slower the better.
This rod has worked well for me on cast iron:
This rod has worked well for me on cast iron:
historicalarms
Ultra Member
Personally, I think I would mill that break roughness out to a nice flat finish and then mill a filler in to match the original vise frame and bolt it through the meaty part of the vise body. it will be as strong and quite possibly stronger than a welded repair, especially when welding an unknown metal composition to another .
DPittman
Ultra Member
I was planning on using bbq to do the preheat but didn't consider using it for the cool down. Unfortunately my bbq is on natural gas on the deck and is unmoveable. It's a good idea tho I never thought of and need to think how else I might make that work. Those electrode you linked look good to me but I didn't see any references to nickel content? It seems most internet advice is using high nickel content rods?
DPittman
Ultra Member
Yes that would be an option also I think. I'm a bit hesitant to do that though because I think i would need to remove the entire length of the jaw width and one end of that is mostly there and the other end is mostly gone. On the top length of the jaw area I would have to probably mill out the threaded holes.
Have you considered using rare earth magnets make exchange of the jaw pairs easy?
There are prefab jaws on the market-nylon, aluminum, maybe copper?
Saves a lot of work trying to drill out the screws, inserting helicoils or trying to drill the 4 new holes.(been there/tried that)
There are prefab jaws on the market-nylon, aluminum, maybe copper?
Saves a lot of work trying to drill out the screws, inserting helicoils or trying to drill the 4 new holes.(been there/tried that)
DPittman
Ultra Member
No I haven't considered that but thanks for the suggestion. This vise will be on a welding bench and will be subject to rough use and potentially hot temperatures. I had considered JB weld and think it would likely be OK if it wasn't for the heat. The drilling out and fixing the broken studs was surprisingly manageable although I haven't yet got them heli coiled yet.
I am not a fan of helicoils. I've put hundreds of them in and have seen issues over time. Time-Serts are much much better. But, since you have a lathe, making up a few thread inserts would also be a piece of cake. Start with a larger grade 2ish bolt and drill and tap the threaded end for your jaw screw size, thread into matching threaded hole in vice body, and cut off flush.. Loctite them in for best results.
DPittman
Ultra Member
Yes I've heard that there were improvements on the heli coils but have not used them nor have I had problems with the heli coils but I haven't used many of them. I just thought they were slick. I'm embarrassed to say I have never thought of turning my own insert
What a great idea.
DPittman
Ultra Member
Ok what am I going to use for new jaws? New boughten replacement jaws are almost certainly not going to have same bolt and alignment t pin holes in them? If I made new ones out of regular mild steel would they be good enough? I think I'd have mill serrations in them somehow for holding/gripping. I'm probably not going to buy tool steel ti maje a new set as I suspect that would be out of my budget for this job.
DPittman
Ultra Member
Thank you but I found some mystery 1x6" slab stuff in my pile so that's what I'm going to use.
DPittman
Ultra Member
Maybe I'll see if I can find hardening compound some day and get the surface of the jaws hardened up a bit.
DPittman
Ultra Member
I'm curious about how the heli coils fail. Do the inserts come out after installation? And if they do would loc-tite at installation solve the problem?
I looked into the Time-Serts and they do look like a better product but WOW they are expensive. I remember when heli coil setups were over the moon price wise too but now there are cheap knock offs available. (I just ordered some off Amazon)
I've had them back out in applications where the bolt is periodically removed. Like a brake caliper mount . A bit of corrosion and they try to back out when the bolt is removed. In aluminum cylinder heads especially they have to be installed one full thread below flush so they don't pull the top thread up when torqued. Using Loctite can be an issue with helicoils too. I've never had any problems with time sert type thread inserts. I've made my own several times too.
I love it when guys like you say stuff like that. I think most of us love DIY solutions. Please tell us how you did it. Might save me a trip to town someday.....
I did a 12x14mm insert the other day. started with a cheese grade 14mm bolt and drilled the threaded end out and tapped 12x1.25mm. Threaded it into the part and trimmed it flush with a zip disk. Next time i'll take pics. Took 5 mins to make. Nearest auto parts store is 25mins from my place.