Date: Thu, 23 Apr 1998 06:40:25 +0100 (WET DST)
From: Simon Trickett
Subject: Cracks!!
Hello everybody.
Does anybody know a skilled alu welder in the south of England. I need a crack in my modified sport head attended to!! it runs between 2 & 3 spark plug holes but not to the holes (yet!)
Also does anybody have a good sport head for sale either Wills Ringed or Standard??
thanks
Simon Trickett (Simon.Trickett@signal.co.uk)
Date: Fri, 24 Apr 1998 07:04:33 +0100 (WET DST)
From: Gary Harding
Subject: RE: Cracks!!
Simon,
Aluminium welding isn't that difficult. It can be done with a domestic MIG welder on full power with Argon gas. But, the job must be pre-heated, I believe to around 200 degrees Centigrade, so further damage to he head may result. At the very least the head would need to be skimmed afterwards. I should think the biggest issue would be getting a professional to warranty the job as it will be difficult to check the weld for flaws. While they are still available maybe a good second hand head would be better.
Gary
Date: Fri, 24 Apr 1998 22:48:29 +0100 (WET DST)
From: Simon Trickett
Subject: RE: Cracks!!
Gary,
hello there, yes I can TIG @ MIG weld but do have the facilities.
The head in question is a Hartwell Head which was modified just before Ray retired, I would like to repair it as it cost lots of cash!! I am trying to source a spare head at the mo, I know of 2 castings but the owner is uming and aring about selling them.
Simon Trickett (Simon.Trickett@signal.co.uk)
Date: Sat, 25 Apr 1998 03:53:32 +0100 (WET DST)
From: Bert Clewits
Subject: Re: Cracks!!
Hi Guys,
My cousin once had a sport head which was destroyed by a valve stem which went straight through to the water channels.
The head was welded and the damage repaired it cost him 500 guilders and that was 15 years ago (This being done in Holland). The head was done perfectly and runs fine !
So it can be done !
Bert
Date: Sat, 25 Apr 1998 05:47:15 -0400 (EDT)
From: Gary and Carol Henderson
Subject: RE: Cracks!!
Hi Bert & others
Welded repairs of punched holes and 'mice' (corrosion) work fine & are routine with the older car fleet in NZ. However, cracks have some nasty properties with respect to residual stress concentrations. An alternative is the ancient technique of 'stitching' using overlapped threaded fasteners - there are now aluminium ones with a special turned-over 'grabbing' threadform available made especially for this purpose. Much less likely to warp the head...
Cheers
Garyh
see also: welding aluminium