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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Mex-Busnut on July 15, 2011, 03:58:23 PM

Title: Now I am on crack!
Post by: Mex-Busnut on July 15, 2011, 03:58:23 PM
Dear friends,

Today between two long visits to my dear ailing mother, I went to check on my friends that are working on my bus. The entire floor is now out. I discovered something perturbing: I have a full crack, plus another hairline crack in one of the crossbars that support the front of the Torsilastic suspension! These are visible in the picture, just to the left of the red wire, and directly below the two bolt heads.

My welder friend came over to look at it, and said he can fix it with his 220-volt, 80-amp welder. However, we want to know if it might be better to add some kind of reinforcing plate to this? Suggestions?

What would cause this to happen, and how to prevent it from happening again?

I do believe all the Torsilastic suspension components look like they could use a real good cleaning. (30 years old!) How do you lubricate it? Tomorrow we will give the other end of this suspension a good checkup.
Title: Re: Now I am on crack!
Post by: Chopper Scott on July 15, 2011, 04:10:18 PM
Just make sure you v the cracks out good before welding them and plate over the top and bottom if possible. Do not weld across the ends of the plates in the same direction as the current cracks or you'll have cracks again. Try and get the plates to go far enough to get to other framework if possible. An 80 amp welder is pretty small even if it is 220.
Title: Re: Now I am on crack!
Post by: Mex-Busnut on July 15, 2011, 04:13:04 PM
Thanks, Chopper! Please excuse my ignorance and explain: "v the cracks out good".

Thanks again!
Title: Re: Now I am on crack!
Post by: babell2 on July 15, 2011, 04:27:06 PM
What Scott is saying is to grind a V grove in the crack to allow the weld to penetrate to the full depth of the frame member being welded.  During welding the thickness will be replaced by fresh weld and penetration of the weld will be complete to full depth.

Brice
Title: Re: Now I am on crack!
Post by: bevans6 on July 15, 2011, 04:39:33 PM
Good catch!  Boy, those are nice.  Classic frame cracks.  As stated,  grind the cracks full depth.  I don't think an 80 amp welder is enough, I would hesitate with my 170 amp  220 volt welder but I would probably do it.  I wouldn't touch it with an 80 amp welder.  The amps refers to the DC amps at the electrode, not the amps drawn from the supply, btw, so the 220 volt part is kind of moot.  You really need a good welder (person with experience, not welder machine) to do this, and I would plate across the whole member with .100" plate.  A really good operator can make a decent if small machine stand up and do tricks that a rookie can only dream of, and I know that you have great operators in Mexico.
Title: Re: Now I am on crack!
Post by: chev49 on July 15, 2011, 06:38:41 PM
besides the above mentioned, i would use a really thick stuff  like maybe c channel the right size and drill a buncha holes for plug welding as i was welding the thing on.. but i like overkill. and make sure all metal is properly cleaned before welding.

Title: Re: Now I am on crack!
Post by: robertglines1 on July 15, 2011, 06:45:40 PM
you know being in Mexico and using that word : you never know who is lurking.  Just kidding. Sounds like you have it covered. Clean - V -reinforce =better than new.  take time don't overheat surrounding area.
Title: Re: Now I am on crack!
Post by: belfert on July 15, 2011, 07:16:50 PM
I would be a bit worried about how the metal cracked in the first place.  I wouldn't imagine Mexico uses salt so it probably didn't rust too bad.  I've hard that Mexican roads are really bad so maybe it just broke from the roads.
Title: Re: Now I am on crack!
Post by: Mex-Busnut on July 15, 2011, 07:35:37 PM
Quote from: belfert on July 15, 2011, 07:16:50 PM
I would be a bit worried about how the metal cracked in the first place.  I wouldn't imagine Mexico uses salt so it probably didn't rust too bad.  I've hard that Mexican roads are really bad so maybe it just broke from the roads.

That is what I want to prevent from happening again. Yes: We have some great roads and some terrible ones. Any preventive ideas are appreciated!
Title: Re: Now I am on crack!
Post by: Brassman on July 15, 2011, 08:04:51 PM
Only an expert could repair that in place. Cracks are like mice: see one, there's more.
Title: Re: Now I am on crack!
Post by: demodriver on July 15, 2011, 09:04:47 PM
Usually a crack that has been welded up will recrack some where.   

How long is the piece of tubing? Is there very many brackets on it?
The reason I ask is because if it was mine I would like to change the whole tubing and add some braces.

Is there a reason that the piece was over stressed? Bad suspension parts? Or is it just fatigue from age?

Eric
Title: Re: Now I am on crack!
Post by: Chopper Scott on July 15, 2011, 10:34:19 PM
Take it too a welding shop and let them do it right. Nothing against your buddy with his little welder but he really probably doesn't have a clue or he'd give you the same advise. If it's easy access and I'm not laying on a piece of cardboard trying to weld up the underside, (I add for burn't scars on my arms!) I would think 2 or 3 hours tops. If you bring it to me after your buddy welded it up it would probably be more like 5 hours and even more scars on my arms!!! Buddies can cost you a lot of money unless they do stuff like this for a living.
Title: Re: Now I am on crack!
Post by: Chopper Scott on July 15, 2011, 10:36:21 PM
Quote from: demodriver on July 15, 2011, 09:04:47 PM
Usually a crack that has been welded up will recrack some where.   


Eric

Not at my shop!
Title: Re: Now I am on crack!
Post by: chev49 on July 16, 2011, 08:50:35 AM
Yeah, part should be removed... and no telling what else you would find... orig part needed to be stronger in the first place.. thanks to the engineers ;D,... and you could build a new one 3 times stronger.. but it would help to have some professional equipment as stated in the previous threads, cause it's hard to build things without real welders, grinders, plasma cutters, lathe and the like
Title: Re: Now I am on crack!
Post by: Lee Bradley on July 16, 2011, 10:07:38 AM
Plenty of rust in the sheet metal to the right and looks like that beam is rusted out at the bottom between those cracks.  I would replace the beam.
Title: Re: Now I am on crack!
Post by: John316 on July 16, 2011, 12:55:05 PM
Quote from: Chopper Scott on July 15, 2011, 10:36:21 PM
Quote from: demodriver on July 15, 2011, 09:04:47 PM
Usually a crack that has been welded up will recrack some where.   


Eric

Not at my shop!

LOL, Scott, I actually thought of you, when I read that. Most welders I know take those kind of comment very personally ;D
Title: Re: Now I am on crack!
Post by: robertglines1 on July 16, 2011, 05:01:49 PM
Simple make repair best you can: stop by Chopper Scott let him ck it out and improve if neccessary.  On your way North.
Title: Re: Now I am on crack!
Post by: demodriver on July 16, 2011, 06:06:54 PM
My comment was referring to if the crack was just welded together and the cause was not fixed. Wether it be rotten material, over stressed, or what ever the cause.   It needs the tube replaced IMO.
Title: Re: Now I am on crack!
Post by: robertglines1 on July 16, 2011, 06:43:46 PM
It is common in Mexico to over load everything past their capacity.  A bus full of passangers plus freight stuffed in every possible vacant inch. I would doubt it will ever see that abuse again.  It was common practice in the Us until the DOT caught on..Maybe still goes on??100,000lb  gross buses.Add that to less than even our worse roads = real stress. Point being Restore to original state and it will in all likely hood never see that kind of load applied to it again in it's new RV use. Just  a observation.   Bob
Title: Re: Now I am on crack!
Post by: zubzub on July 16, 2011, 08:45:44 PM
My 2 cents, plate and weld it.  Also do the  other side as this looks a little under  built, so the other side will go soon.  I know in Mexico if you go to a truck garage specializing in frame/structure work this will get done right.