Welding on car roof Q

[jobin]

Will be fixing the bike rack very soon.  My  1998 Opel has, on both roof edges, usually covered with molded plastic, a water channel.  I've removed the plastic, totally unneeded now.  This channel has in the center a projecting upright piece about 5mm tall.  The thickness of this steel is about 1 or 2 mm.  I plan to weld a strip of angle iron onto the upright piece in 2 places on each side giving me 4 supporting members.  Then onto these i'll be fitting, maybe bamboo, strips to support the bike.

 

Q for you guys is what is best thickness of angle iron?  I'll be tacking along top and edges of projecting piece.  

[Lancashirelad]

Sorry to say but sounds like an unsightly bodge job. Cars are made of thin steel, angle iron is usually quite thick. Welding 2 metals of different thicknesses together is not easy. I would suggest searching lazada and/or hardware stores/Amorn shop for some kind of clamp instead. A photo of the section might bring suggestions from others.

Edited June 19, 2017 by Lancashirelad
typo

[jobin]

How right u r Lad.  I gave it a shot but started to burn up the car metal before melting the angle iron.  The differential was too great for me to handle: i'm a welding beginner.  I'll try a auto body shop.

I would use clamps but there is very little space.  I will look again, maybe a tiny bolt could fit.

[tifino]

 

botch it enough, and it may become noticeable to a Land Transport Dept patrol

 

 

 

[Lancashirelad]

19 minutes ago, jobin said:

How right u r Lad.  I gave it a shot but started to burn up the car metal before melting the angle iron.  The differential was too great for me to handle: i'm a welding beginner.  I'll try a auto body shop.

I would use clamps but there is very little space.  I will look again, maybe a tiny bolt could fit.

Hope you remembered to disconnect the battery before welding, if not it can damage the diodes in the alternator.

[kartman]

4 pieces of 2mm thick 35x35 mm x 100mm long angle iron cut one side down to just under 20mm  2 6mm holes in that side place in roof side of water channel  35mm side against centre  (can position where factory holes in plastic strip are may be able to re-use) drill 8 6mm holes down through channel and roof lining (will have to remove all the upper plastic trim panels and lining to avoid) 8 button head bolts from the inside washers & nylok nuts in channel you then will have 4 100 mm stripes about 30mm high you can weld or bolt to,Bob's your uncle job done.