would you trust these welds....

[LaMojo]

When I bought my EV back in 98, having a chrome molly frame was an extra benefit of owning a Moto Guzzi.  I don't recall if it was in a sales brochure, owner's manual or just where.  That information may also be in two or three Guzzi books I have. I'll see what I can find..   In the mean time:    https://www.motointernational.com/about-moto-guzzi-motorcycles andhttp://www.themotocycleshop.com/moto_guzzi/mg_used/mg_u_1998_V10_Centauro_Stock/mg_u_1998_V10_Centauro_Stock.htm

[LaMojo]

In doing some quick research on Chrome molly frames:  The California series including the Bassa and Jackal lists FRAME: High tensile stress modular duplex cradle.  2010 California Vintage has the same spec.  My quota- FRAME:Double steel rectangular bar with double cradle.  The Centauro, Daytona, Sport specs FRAME: chrome molly steel frame.

I was wanting to do some welding on a Jackal a few years back but was cautioned at the time that it had a chrome molly frame so I backed off.  Other than a couple of reference supporting that,  I haven't found a direct link that the High tensile stress steel refers to chrome molly. 

Whatch think Chuck. 


   

[cleatusj]

If my '93 is cm it is the thickest I've ever seen. The tubes are the same thickness as my '76 Convert.

[Chuck in Indiana]

In doing some quick research on Chrome molly frames:  The California series including the Bassa and Jackal lists FRAME: High tensile stress modular duplex cradle.  2010 California Vintage has the same spec.  My quota- FRAME:Double steel rectangular bar with double cradle.  The Centauro, Daytona, Sport specs FRAME: chrome molly steel frame.

I was wanting to do some welding on a Jackal a few years back but was cautioned at the time that it had a chrome molly frame so I backed off.  Other than a couple of reference supporting that,  I haven't found a direct link that the High tensile stress steel refers to chrome molly. 

Whatch think Chuck. 

I'd say that High tensile stress steel is salesman speak for plain ol 1020.  If you *do* have a Chrome moly frame to weld, use only gas or TIG with the appropriate filler rod.
I've only seen one failure on an aircraft weld, and it was arc welded. Stinson used to have a huge annealing furnace, and they had special dispensation from the FAA to arc weld their 4130 fuselage, put it in this really sturdy  jig, roll it into the furnace, and stress relieve it.
Broke anyway in a fairly minor crash. I repaired it with ox acetylene.


   

[Muzz]

I remember seeing a photo of the old 350SL Honda off roader they built. The guy was waaaay up in the air, he was standing on the pegs and the bike was about horizontal. The forks too were horizontal.....held to the bike with some wires and a couple of cables. Don't know if he survived the landing but I think it would have ended in tears.

The first of them were made with chrome moly before anyone knew of the pitfalls; I gather they went back to normal steel after that. One guy who desert raced them reckoned he had written off three frames and had yet to blow a motor.  Don't know whether that one is true or not.

[motrhead]

Globbing on weld with a MIG gun or stick doesn't make things stronger. Lots of chance of trapped flux/slag and porosity especially when you downhill. Most novice welders downhill because gravity pulls the puddleover the electrode and doesn't blow through the base metal. There are downhill welders and it is a speciality practice typically used in the pipeline industry. TIG is clean and there is little to no change of trapping flux/slag or having voids. Basically because there is no flux/slag created in the process and you can see if there are voids.

 Ok, background: I've been a pressure welder, production welder, mig, tig , whatever...lots of aluminum, stainless, 8620 etc, etc...no titanium though since school...just so you know where I am coming from. I used to build trailers...thousand s of them, and they were all MIG welded. Guess what direction we weld vertical with MIG? Down. I had Ford training to stretch motorhome frames...with MIG. I would never have chosen that process myself, but Ford did. MIG is holding the world together. It is the most commonly used process there is...and yes I ran my share of big flux core building industrial gearboxes, truck axles, big trailers etc.  I much prefer fabricating to welding any day, but over the years I have done most processes.  Welding pipe is the most boring tedious job going! LOL.
 TIG is for the choice for alloys and is nice for aluminum (though I did a lot of production welding aluminum with a spool gun down to 14 gauge, and stainless with a push pull gun) and extremely thin sections, but it is not needed for plain old 1018 or 1045 material (like an old Italian bike frame). Yes, TIG is clean, and pretty, and if you really can't weld and need to be 100% sure you got it right, by all means go ahead. But it is hardly necessary on mild steel. As long as you aren't getting cold lap, a MIG weld is a good weld.
 I am serious about the poor profile of most TIG welds. Remember that TIG filler rod is a plain old 70K tensile material, same as 7018 electrodes or ER70-S6 wire. I would rather have a 100% MIG bead than a 60 percent TIG bead on plain steel. If a welder is proficient with TIG  and takes the time to get a proper weld profile it is the ultimate, but it is slow (especially when you have to set up backpurging like with stainless).
 I do recommend that anyone welding their own bike frames go take a course at the local community college to get the basics down and make sure their welds are penetrating properly and not cold lapping...but it isn't rocket science!

[cleatusj]

motrhead, I will admit to not having any formal training, but I did pass certification for vertical up, after only running four or five  joints that way. When I started welding, I ran all vertical joints down hill for years, before I was able to watch someone weld up hill.

[motrhead]

motrhead, I will admit to not having any formal training, but I did pass certification for vertical up, after only running four or five  joints that way. When I started welding, I ran all vertical joints down hill for years, before I was able to watch someone weld up hill.

 Mig is generally run downhill unless it is a large weld. I only go up with stick...

[cleatusj]

Stick I s what we use on a boom lift welding clips on buildings for wind load for curtain wall glazing frames.

[Calijackalbob]

The welding looks robust enough for me, I just think that when all's said and done, after an impact hard enough to break forks and twist the headstem, the rest of the frame will be bent, warped, twisted, somewhere or everywhere. I wouldn't trust that. If it was me, I'd be buying another bike with a trashed motor and switching the donks.

GOOD LUCK !  :Beating_A_Dead_Hors e_by_liviu

[cleatusj]

Update. After a couple thousand miles, with a third being rough gravel, no cracks or movement can be found, even with heavy magnification. Many of those miles were with the chair in the air.

The rig is handling better than it did stock. JFYI

[Chuck in Indiana]

  So you mean the doubters were wrong ???

 Dusty

Wasn't me. I said..

I would say not pretty but stuck.   A stick welder would be the last method I'd choose for that job, though.

[cleatusj]

Did not say that, besides they will make up their own minds any way. 

[oldbike54]

 Since we have refired this thread , someone please clear up the chrome moly issue . My understanding is that only the early V7 Sports had moly frames , everything else is built from regular steel . Yeah I know what certain experts say , but there seems to be some uncertainty .

 Dusty

[tazio]

Mr.cleatusj,
My first vocation is welding, second one is machine tool technology.
I'd go for a fly in your chair anytime..

[swooshdave]

I did not ask a one of you to trust my welds, but I sure trust them over half the great looking mig welds I've watched others lay down. I have no doubt as to the penetration.  The neck is straighter than several stock Guzzi frames that the factory chose to sell.

I buy and build my bikes to ride and ride hard, if you do less that is your problem.

I have never said that a pipe/boiler welder could not weld, but most that I have met seem to think no one else can and if stick is so bad why is that the way bridges are welded.

 

[lucky phil]

TIG,MIG..... Pha, give me this for Chrome Molly any day. Welding art.

Ciao

[rodekyll]

lol
What part of this weld job was a bridge?

I'm not suggesting anything about stick welding or if it was the right tool for this job, and yes, I would trust your welds -- they're better than mine, and mine work.  But unless mild steel hollow tubing is bridge material, I don't think the argument works.

[charlie b]

I have to laugh a bit.  My welding looks like Cletus'.  And, yes, sometimes I have to grind it back down and lay another bead cause there wasn't enough penetration the first time.  I don't care how it looks as long as it is a good joint.  I do tend to avoid 7018 rod cause it has to be kept in an oven or airtight container to keep moisture out of it, but, it is a good choice for the job.

Why a stick instead of MIG?  Cause I have been too cheap to buy a MIG or TIG.  :)  Got my Craftsman box from my father-in-law years ago and it works.  And, yes, I have used gas, but, I am not good at it.  I wish I was better.  Someday...maybe...

I'd love to be as good as some of the women during WWII.  Seeing the bead of aluminum along the wing fillet of a P51, done with gas, is just beautiful.

[Chuck in Indiana]

I have to laugh a bit.  My welding looks like Cletus'.  And, yes, sometimes I have to grind it back down and lay another bead cause there wasn't enough penetration the first time.  I don't care how it looks as long as it is a good joint.  I do tend to avoid 7018 rod cause it has to be kept in an oven or airtight container to keep moisture out of it, but, it is a good choice for the job.

Why a stick instead of MIG?  Cause I have been too cheap to buy a MIG or TIG.  :)  Got my Craftsman box from my father-in-law years ago and it works.  And, yes, I have used gas, but, I am not good at it.  I wish I was better.  Someday...maybe...

I'd love to be as good as some of the women during WWII.  Seeing the bead of aluminum along the wing fillet of a P51, done with gas, is just beautiful.

I've done a little of it. It's done with oxy hydrogen and special goggles. You really have to move fast.  Some of the best ox acetylene welding I've ever seen is on the fuselages of Taylorcraft aircraft of the 30s and 40s. There were two guys that did it, and it is truly beautiful. 

[CapitalGoose]

Those look pretty nice to me.