just a bit of advice for my project

[gtimad73]

hi all. im a bit of a car modder, and want to weld in a vent to my front wing. i was thinking of welling it from the in side so i wouldnt have to grind down the finished side to much. does any body see a problem doing this? and the other question i have is should i cut the hole in the wing the same size as the piece im welding in or over lap it. what would give the best resultes. cant wait to start burning holes in my car with my nearly new clarke 160en. think i got a bargin for 45 quid. please dont tell me there rubbish.
any info would be good.

 

[Haze]

it shouldnt be too hard to cut out the exact size hole you need, and attack it from both sides, with liberal use of the grinder afterwards, small tacks in the corners, and another 1 on each straight edge, weld in inch long increments and let it cool in between, you dont want to warp the panel.

 

[gtimad73]

i'll have the wing off the car. so my idea was to weld from the back. then id only have to grind the penertaion marks out. does that sound ok? as for cutting the peice the same size would that just make it easyer to fill late? or is that the proper way to do it??
thanks for the help so far.

 

[malcolm]

Do you have a photo of the part you want to weld in? I'd always weld from the outside. There's more weld build up to get rid of doing it that way, but it should be a more consistant surface than the reverse of the weld which makes it easier. Handier for lining up when you do it from the outside too.

I'd normally trim the hole and the bit you weld so they fit together edfe to edge for a non-stress bearing panel like that. Again ends up neater and with nowhere for water to be trapped.

Finishing the weld is really quick and neat with gentle use of 40 grit flap discs. See http://www.mig-welding.co.uk/finishing-welds.htm (cheating a bit there as the panel is curved which makes finishing easier).

 

[gtimad73]

sorry i dont have a pic at the moment. thanks for the advice. im just trying to get all the ideas in my head so i get the job done right. and dont make an **** of it. but will get a flap disc seams to work well.

 

[Rusty]

I would consider plug welding it from the inside,you would need a flange around the edge of the vent and drill / punch some 6mm holes
about 40mm apart, providing you dont blow holes through the wing there should be very little cleaning up to do from the outside, just make sure you seal the join inside the wing with something like seam sealer sticks like s$£t to a blanket ! Otherwise you will have a nice water trap !