I would have to start by seeing exactly what the paper work says regarding what work the welder was to perform.

The part was NO good in the broken state, so he elected to have it welded.  It was broke anyway, so why should he be paying back charges for trying to fix it?  You stated "I feel this weld was not done to an acceptable standard whatsoever, and he should be back charged for his shoddy workmanship", so what was the code or standard that was discussed prior to the welder doing the work?  What were the workmanship requirements?  I'm not sure of any code or standard that addresses cast aluminum engine block welding repairs.  I think you are way out of bounds on your assumptions. 

Your next statement "The block was not sent through a hot isostatic process, nor was it put in an oven prior to, or even after (he could have even used vermiculite...) doing any and all of his passes".  Now I ask:  So what, did it need to, was local heat from the arc enough to get the job done??

And the next one "I feel that his work is the direct cause of the malfunction of the rear engine mount (leading it to be ripped out of the block), as this has NEVER happened on any block that has not had to have been repaired".  Now I ask:  Why did the rear mount need to be repaired in the first place??? Hummm, now that's interesting.

And now the best of all: "From what I've been told from several veteran welders, is that the block should have been replaced in the first place. If a repair WAS attempted, it should not have been done with TIG, but MAPP/Propain gas torch and special filler metals. The block should have been prepped properly (HIP, heat oven cooling)."  Now, I don't know ANY welder that would repair aluminum with this process

You asked us for our references, but before giving that, what are yours???

It's hard to really see, but it looks like there is spatter on the part.  GTAW (tig) would not have produced so much spatter, so maybe it was GMAW (mig) welded.  In any case, GTAW would be the process of choice to make such a repair.  Some aluminum castings are not well suited for welding repair.  The welder should have told the guy that is may or may not work.  I have repaired many engine and transmission parts, some are still in service, some probably not.  I have always informed the customer that you part was broke when you brought it here, and I will do my best to fix it, but sometimes it will not work no matter how you do it.  In either case I'm going to charge you for my time and materials.  If you choose to leave without having it fixed, that's fine, if you want me to do it there is not a guarantee on the fix.

You're wrong, the guy tried to do a good job on some hard stuff to fix.  If you know so many welders and got such good information from them, why didn't one of those guys fix it???

Mark

The procedure you describe sounds appropriate for welding aluminum.  If the bolts were ripped out of the holes, then I would be looking closer at the drilling and tapping of the new holes as a possible cause.  Sounds like the bolts could have been cross-threaded or the threads stripped by over tightening.

   I agree with those above, and MBSims in particular.

   If You heat an entire engine block [to a temperature much above operating temperature] You run a great chance of having severe distortion on all the critical surfaces. Unless You expect to re machine all of them, which is usually impractical and sometimes impossible. If You are suggesting that the weld deposit should have been a heat treatable aluminum alloy and the repaired block put through a heat treat cycle, You are way off base.

   The weld deposit did remain attached to the block, so there must have been sufficient fusion in spite of lack of pre heat, and post heating/ delayed cooling would not have increased the mechanical properties of the weld deposit.

    I would agree with the guys who suggested replacement of the block in the first place. With regards to the low temp aluminum solder Your vetran welders mentioned, it does work well for soldering nail holes in beer cans, but I am unsure that You will have sucess on a 300# engine block with it.

    If the engine is in good condition and the material around the stripped holes is sound, You might try helicoils. If You are drilling the holes with a hand held drill and hand tapping them, You will probably tear out the helicoils too.

    

It's hard for me to tell by the pictures what was done. I have welded Alum. engine blocks using GTAW DC Straight Polarity with Helium and have not had a problem. It was for the most part a patch where a rod came through the block.

Thanks
Jim

Code-Red,

/quote Lawrence/

"...The fellas have covered everything here...  I"m sure you don't like the answers, but your hearing them from from the best professionals on the planet and not some hack pal who uses pop-can solder he bought at Home Depot or the Farmers market."

/unquote/

This is pretty true.

Thus it's normally unneeded to add something.

However, just as a very short remark to this from my side, based upon what Jim Hughes has posted.

There is a patent granted in Germany to the MTU company (Maschinen und Turbinen Union).

They have "developed" the so-called AGL-power source or process respectively, (A = Aluminium - GL = Gleichstrom) which stands for GTAW Aluminum Welding under Helium with DCEN polarity. Although it is idle to discuss if they were the "inventors" of DCEN GTAW Aluminum under Helium, the process itself is quite interesting.

It allows actually to weld greater wall thicknesses e.g. cast aluminum motor blocks without the need to preheat or remove them prior to welding. This is due to the intensive and tight geometrical area of heat input. Its being used in a wide field where submarine- or in general large ship motor blocks have to be repaired (e.g. in case of cracking).

As far as I know its being accomplished with great success without preheating the heavy AlSi-cast block.

I have tried to find two reports about the use of the process being contained somewhere in my trade journal collections, but I beg your forgiveness, I haven't found them and it would take too long to continue the search - although I know they are there.

I have tried to google the articles but the only document I found is a kind of leaflet from a German company (MAUDERER) using this process (patent) to repair large walled AlSi cast motor blocks without preheating or removing the block or to weld large wall thicknessed Aluminum constructions. I'd like to attach the document here, but I apologize for that it's written in German.

However, it doesn't matter, since I think the hint coming from Jim Hughes, additionally to what's already been posted by the other experts is worth Gold. I mean the usage of Helium - patent to and fro - might be worth a try at least.

You have to consider however, that the arc ignition might make some problems when using Helium, since it needs a higher voltage. But it depends upon the power supply and if so you might try striking the arc.

Helium finally could make sense in your case...

Just my humble opinion.

Thanks and best regards,
Stephan

Code-Red,
is this a Ford Escort block? If it is its a whole different world.

Jim