Car floor repair 'bodge'

[SiPMerlin150]

think ur not allowed holes within 30cms of a strucural component.... not sure?

correct, but once welded properly, there as good as new! Having corrosion, or holes with 30cm of body mountings, structural load bearing areas, is reason of MOT failure.

 

[jonnyBMX]

yeah, welding my mini up from the bottom up... but i did mig it and i cut all the repairs in so you cant see where any of its been done

 

[SiPMerlin150]

yeah, welding my mini up from the bottom up... but i did mig it and i cut all the repairs in so you cant see where any of its been done

As long as you have full penentration of each weld, and its a full 'seam' weld all round then its passable, one tip though, when the time comes for MOT, keep the underseal off the new welded areas, just so the mot tester can see the work done and be satisfied. Or, if you are on more friendlier terms, go ahead and zinc prime coat the new areas, then underseal with a quality underbody schutz.

Note: Depending on your skill, you might burn holes in the metal with your mig, are you using gas or gasless? Gas bare wire is better as its ever so slightly cooler and you can see what you are doing! A little method is to use short burst of tacks to reduce the risk of burning through. make sure the tacks are fused well into eachother leaving no gaps . This will reduce the chance of a cold weld. Just don't use arc like I did!

 

[jonnyBMX]

ahhh... ive been miggin for about 3 years buddy! never really burn holes in sheet metal now, i weld cars for MOTs on a daily basis and litrally most of my repairs where practicle are invisable as i cut the metal out, but weld it in and if needed grind flat the welds

but thanks for the tips,

one thing i do normally do is go round tacking it in at 1" intervals to stop any warping, and if its a big plate make sure not to put too much heat into it or the panel will warm, espicially if its on the outside!

also a quick a question... you say zinc prime... thats weldthrough primer... i would normally use this stuff before i have done any welding such as on two panels which have to be spotted toghether (or plug welded) such as the flanges on mini panels...

if i am spraying any bare metal areas i would use etch primer which effectiverly etches itself into the metal. then would put a high built primer over that. then probably use gravitex stonechip sheild or some kind of underseal depending on where it is...

 

[SiPMerlin150]

ooh, you dont want to weld through zinc..fumes are very poisonous, expect fume fever, like a really bad hangover and gives you bad trembles.

 

[jonnyBMX]

so your saying DONT weld through weld through primer?? what on earth would be its use if you dont haha!!! ive never had any of those symptoms, i guess if your welding in an enclosed space you might, but if so you can use air fed masks...

anyone else got any thoughts on zinc rich primer? otherwise known as weld through? what do you use it for?

 

[Chickenjohn]

use zinc rich primer on the inside of box sections you are closing by welding and on the INSIDE of plug welded overlapped seams. Any exposed accessible areas, keep as bare metal while you weld as these can be painted over after welding.

As for any zinc fumes, just work in well ventilated area/ wear a mask.

 

[jonnyBMX]

chicken! exactly as i thought! i use it on the inside of flanges between bodypanels ahha! obviously its best to keep it bare metal but for those areas you wont be able to paint afterwards its the only way to go!

and then on the bare metal etch prime

 

[Chickenjohn]

Exactly! You don't use weld thru on what will be the outside of the repaired section.

 

[SiPMerlin150]

so your saying DONT weld through weld through primer?? what on earth would be its use if you dont haha!!! ive never had any of those symptoms, i guess if your welding in an enclosed space you might, but if so you can use air fed masks...

anyone else got any thoughts on zinc rich primer? otherwise known as weld through? what do you use it for?

Sorry, i've no experience using weldthrough primer, i'm a little paranoid when it comes to zinc or galvanised i've always primed with regular primer after the weld was cool and tidied up, then a nice coat of sticky underseal.

Apologies for my dumbness

 

[jonnyBMX]

haha its okay, its kinda neccesity while working on cars if you dont want the rust back in 3 days! lol! i got so many different kinds of primer its unreal! costs alot to get set up for car repair but now its good money