1970 Ginetta G15

Righty then - welding 0.9mm aluminium - LOL


I didn't help myself at all with this one

First off I made a shonky cut with some snips on an edge that had been thinned due to bending trying to weld the two parts together with a sort of but weld suspended in mid air using a filler rod twice as thick as what I am welding. And it was a horror show.







It did exactly as I thought bit would - As soon as the arc was struck it just melted back opening up a chasm - but being a bloke and doing what blokes do - hit with more heat LOL.

Stopped and had a think and figured I needed to soak a bit of heat so I backed it with a bit of stainless angle that at least enabled me to weld melt some bits together.







This was welding on welding just trying to fill the horrible burn back holes with tungstens getting contaminated - It was dreadful.


So I did the same again ......... Cut another strip right on the bend and this time started with the stainless backing from the off. - It was only mildly better.













I did try a run or two just on the face of the box - and no problem I can hold a weld pool in 0.9mm no nproblem.


Had dinner and watched a couple of you tube vids on welding thin alloy .

Well the pro started with really thin 1.6mm ! - warned about using too thick a filler rod for the material and made some filler rods out of 1mm mig wire - "other wise you cannot fill" - he only had 3 mm rods and the issue will be the 1.6 plate will melt and all the 3mm will do is ball on the end of the rod. Lightbulb moment - Ah that's why my 1.6mm rods were balling back trying to weld 0.9.

He then moved onto really ultra thin "tin foil" 1.0mm ! loads of effort with cleaning and making sure absolutely no gaps on the 90 join all nicely guillotined - and with 1.0 mm filler rod.

Lovely weld as you would expect - perfect set up bench etc. etc. - but what struck me was the amount of parent material that was being used up as well as filler rod - what started as a razor edge 90 ended up with a very rounded bead probably taking the peak down at least 2mm.

Hmmm

Okay for a final hit even with a filler rod far to big lets try running a bead on top of the bend - which is 0.8mm







So

The trick is when you fold these make sure that the end is a 90 degree joint - the welding will consume the material and give you a nice radius - also making something from 0.9 - for sake do not bother unless you really have a masochistic streak. For scale that final bead on the top is 4.5mm wide - I probably could have done better with a smaller filler rod.

The water tubes were only 1.6 ! - Must be a US thing that anything less than 1/8" is really thin material.

So will and make a "really thin" 1.6mm alloy cube next.

2.0mm for a fuel tank will be a walk in the park.

Extended the Easter holiday with a couple of extra days off tacked on each end and this morning was set aside to collect the G21 from Itchy's place where it had been sat for far too long due to the travel restrictions.

Used the replacement Mitsi tow barge whilst the L200 is waiting for me to glue some steel into a couple of places on the chassis. The L200 has been replaced for daily duties by the ASX but the L200 will still be with us as a standby and lanes hack as Mrs DS does not like getting her new car dirty.

Quite nice having mod cons like a reverse camera for sighting the tow bar, buzzers and bells that tell you one of the trailer indicator lamps is intermittent, and a rear window you can see out of. Shorter wheelbase helps as well.







Now got to find somewhere to keep both the G21 and the trailer for a bit as I do not want the front overrun with cars again as there are too many already.

stunning wee machines

Some time ago I helped out a guy who was making a batch of stainless steel window frames for G15's - I bought two sets for myself - BOY and KBW (now with molebert) and bizzo bought a set for PHX - I cannot recall now if the guy made 10 or 20 pairs - anyway he had quite a lot of complaints about them from people who bought them and kind of responded - sod the lot of you, you ungrateful - and vowed never to have anything to do with Ginetta's again.

One - I really think he undersold them and should have charged more - I would not have made them for what he did.
Two - Unfortunately he cocked up when doing the final welding and put the window latch lock bar in the wrong place.

The lock bar should be on top of, and not on the side of, the window channel.



He also welded them on good and solid.













So, my task now is to carefully try and remove those sections - 8mm square stainless and replace them.... I hope its a little easier job than I think it is going to be.

Agreed - they should slice through it easy enough and once the top tacks are through and the lower welds "thinned" I should be able to 'crack' the remaining weld by careful levering if not getting deep enough. The top of the channel will be hidden by the new lock bar and the side of the channel will be mostly hidden by a lip on the door top that currently fouls the lock bar and stops the frame sitting on the door correctly. I just want to avoid thinning the channel by hitting it with the disc too much (if at all)- plenty of masking tape will be sacrificed to stop it getting scuffed.

Using the small disc in the air cut off tool will allow a lot more finesse. When dressing back I will also use the 2" and 3" Roloc discs so as to take the welds down with plenty of visibility rather than bashing at it with a 4.5" flap disc in an angry grinder.

I need to make a nice clear working space in the garage before I start but I do not see too many issues and the stainless welding should be easy enough.

Cut the welds and removed the 8mm square section










At this stage I had not ordered the replacement SS stock as I did not know how many sets of frames I would be repairing - its quite expensive material even lowly 304 is £32 for 3m + delivery. 3 frames from 1 length. As I have a TIG and stainless wire I figured I would see if I could do a filling/repair job on the cuts.










And then I failed to take any more photos of tacking and welding the bar back in the correct place on top of the rail.

Finished Items - If you know what you are looking at you can make out the bar on the frame and the tacks.










What I didn't do is fill the longer underside slots - These were pretty well hidden when dropped on top of the channel - I should have filled them as it made the welding at those points far harder than it should have been - As its all out of sight it does not matter. When polished up the result is more than good enough, it's not 100% perfect as you can see the difference to a 100% cut flat finish when compared to the flapped wheeled flattened surface but it's pretty good.

Nice work! Didn't know that you could heat fibreglass to change the shape. Is it like woodwork whre you can heat it (in the case of wood with steam), clamp it in a new position and let it cool there and it'll stay?

I've got a fair bit of fettling to do with the boot and bonnet of the Spitfire and that would be really useful if that's the case!

Dead useful to know can hopefully avoid cutting and re-glassing bits to get a different shape in them

Hi John,

He did a good job and I fully appreciate the amount of effort he put in - As I stated I think he undersold them, no way would anyone have ever got close to replacement stainless frames if he had not taken up the task. They are excellent for the cost and he got no complaints from me even with the slip at the final hurdle. A slip I did not even know about until a few weeks back - As I know of 4 sets within my small group of contacts and only one set of those are fitted - PHX - pretty sure it must have been 10 sets he made.

He had this lot there when I dropped in to see him.



Yep - shame it all went a bit sour in the end he would have have been a good asset for those hard to get Ginetta parts.

Do you know how he got on building that car he was working on for himself?