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Posted by: Wyvern Oct 18 2019, 07:17 PM

Looking to replace my battery tray ..
only the tray.

I see loads of info on doing the support and tray .
My biggest question how to remove the tray only?
The long weld I can deal with but to remove the tray from the stand ...
Just keep grinding the tray till it can be separated or cut it down and just weld on top of the smaller "good section left?

Posted by: mtndawg Oct 19 2019, 12:10 AM

http://www.914world.com/bbs2/index.php?showtopic=105978&st=0&p=1303899&#entry1303899

Posted by: Rand Oct 19 2019, 03:53 AM

Only the tray. This should become a new quote here.

Posted by: Rand Oct 19 2019, 04:00 AM

If you can grind you are good. It is sheet metal.

Posted by: Tdskip Oct 19 2019, 09:32 AM

I did the tray only on the ‘73 1.7 car by drill out welds then cleaning the support metal and using weld through primer. I used a MIG to replicate the spit welds.

One tip is to make sure the ECU mounting points locate the ECU properly prior to welding,

Posted by: bbrock Oct 19 2019, 09:45 AM

I'd pick up a Harbor Freight spot weld cutter to get the tray out. The HF cutters suck, but are good enough to get a tray out and easier than grinding.

Posted by: dr914@autoatlanta.com Oct 19 2019, 09:53 AM

i agree that is what we do. wire brush first to reveal the spot welds makes for a much more precise cleaner job

Posted by: Wyvern Oct 19 2019, 04:55 PM

Thanks to all .
I'll try the HF tool and if that doesn't work will use a grinder.

Posted by: Rand Oct 19 2019, 05:09 PM

I really wish you would look under there. If the tray was rusted through then more important bits are taking the hit.

Posted by: Wyvern Oct 20 2019, 12:08 AM

Good advice ... it really is only the tray ( Hell hole . & support are good . with just a bit of work) .
I am prepared to do more but will dissect piece by piece .

Posted by: roblav1 Oct 20 2019, 07:34 AM

Agree those HF cutters are awful. Cobalt drill bits seem to be better.

Posted by: bbrock Oct 20 2019, 09:15 AM

I found them to be good for about 5-10 welds per cutting side before they either shattered or went dull. Awful, but good enough to get a battery tray out for just few bucks. For serious spot weld cutting, the Blair Rotabroach is hard to beat. Awesome kit.

Posted by: IronHillRestorations Oct 20 2019, 10:57 AM

I mark the spot welds with a punch and use a Blair Roto-Broach https://www.blairequipment.com/rotabroach-cutters to cut the spot welds. You can get several different cutters for the same arbor. Not cheap, but if you use them carefully (keep it square and don't wobble) they last longer than other cutters I've used.

Practice making plug welds on something that isn't your 914 (using similar gauge metal), before you want to weld the tray in. When you are good and ready, practice some more.

Fit the pieces carefully and make sure it's properly located and the mating surfaces line up good before you tack anything in place. I drill and dress up any holes for plug welding, so you get a good fit.

I use weld through primer on both surfaces, my favorite is U-Pol #2. It's not for the actual welds, but IMHO it's the best thing you can do for the metal surrounding your welds. I used a dental tool and scratch off the primer in the holes before I plug weld them. You don't have to do this, but I've found it makes it easier to strike an arc and weld.

The hardest part is welding the tray to the inner fender wall, and if that wall isn't solid it adds to the difficulty. You can make welds along the top edge along the wall, but it's hard to get in that gap.

Posted by: Rand Oct 20 2019, 12:25 PM

The spot welds are piddle. If the tray is rusted, you have to look deeper.