Never welded before - how hard is a sill job?

[rbgos]

I used to own a '73 Black Tulip BGT, until it was accident-damaged and written off (NOT my fault!) about 6 1/2 years ago. This weekend I went to look at a near-identical car for sale near me.

This car has been off the road for some time, but looks in quite reasonable shape (for the price!), and shouldn't take much too get it roadworthy again (I hope!). The only major body problem is the drivers side inner sill - or rather lack of it! The outer sill is there and mostly sound, the upper inner sill (what you can see from inside the cabin) is fine, but the lower inner sill is pretty much non-existant (I hope I'm making sense!). The jacking point is barely hanging on, and part of the tranverse floor stiffener is pretty bad, although the floor itself is sound enough. Apart from this, the body is pretty sound, just the occasional surface rust patch that you'd expect, and a 1" hole in the front wing - the passenger side sill looks perfect, oddly!

Anyway, my question is this - for a home mechanic who is pretty competant, but has never learned to weld, how stupid an idea is it to make a sill job my first learning welding experience? How much (in the UK) should I pay for a useable welding kit?

Thanks a lot,

Richard

 

[Radford]

Welcome to the Forum Richard!

While I am afraid I can be of no help as to the price of welding equipment in the UK I can point you to a series or posts that might give you some idea as to what sill replacement involves. Look down about eight or so posts back for John Moore's post "Sill Replacement" - oh and take the time to open his attached photo.

Good luck!

Rad

 

[usasma]

You'll need someone to evaluate the quality of your welds. Years ago I was a welder for several months and finally ended up losing that job because of poor weld quality (which wasn't evident to me).

 

[ROADSTR6]

I'm doing mine right now. It's a very time consuming task. Learing to weld on a MIG is not that difficult. You can do this job at home. Be prepared to replace inner, outer, itermediate sills, castle rails, floor pans and dog legs at bare minimum. This is an expensive proposition, as I have come to realize. The MIG welder and associated welding equipment alone was $650. Check out prices for all the panels I mentioned and add a couple hundred dollars minimum for extra stuff like jack points, reinforcers, sill caps, paint, abrasives, etc. It really adds up fast. IMHO you are better off passing this car up for a more solid car. I wish I had.

 

[RichC]

I will second Roadstr6's comments. If you only have one sill, it might be best to have a professional welder replace.

Often people are like me ... restoring the car is only half the goal ... the other half is the sense of accomplishment in learning new skills and admiring what even 'bumbling amateurs' are capable of once in a while.

MIG is probably the most attractive method nowadays for most autobody welding. (steel and sheet metal) There are cheap models available, but often make the job of making good welds by a rookie all that much more difficult. I think you'll need to spend the equal currency amount to the $650 US for something decent. (here in the US names like Lincoln, Hobart, Miller, etc all make quality equipment) If you are looking to compare ... check out the feed roller for the wire, cables, number of adjustments, cooling fans, and overall weight between cheap models and quality machines. Also ... most welders prefer shielding gas (Argon) v. internal fluxed non-gas feed wire. YMMV.

 

[Dave Russell]

[ QUOTE ]
You'll need someone to evaluate the quality of your welds. Years ago I was a welder for several months and finally ended up losing that job because of poor weld quality (which wasn't evident to me).

[/ QUOTE ]
Very true. With a MIG, it is possible to lay down a beautiful looking bead that actually does not penetrate the metal hardly at all & has no strength. In any welding, penetration without burning big holes in the metal is the main goal. It is much easier to assure penetration with a gas welder or TIG. On the other hand, it is possible to destroy the metal's strength by overheating. I really would suggest learning to do gas welding first. Even better would be to take an evening course in welding at a local vo-tech college. You will learn about heat, feed rates, timing, & materials compatibility. The instructor will constantly check your work for penetration & quality. There is no substitute for practice & evaluating the results. Many people are self taught & eventually learn how to do it right. Some, never do, but "think" they can. I don't believe that the structural parts of a car are a good place to begin learning. On a unibody car a great deal of it IS structural.
D

 

[Steve]

Word of warning.....the outer sill looks fairly good because it is more than likely a cover sill, welded on to get the car through a past MOT.......you will need to replace everything, and on the MGB, to the best of my recollection, the sill assembly is in three sections. Not, I'm afraid, a project for a novice.

 

[Banjo]

Seems a common thread is developing here. I have done sills on a B roadster. But I have some welding experience also. It is VERY time consuming. I would not reccomend trying to "patch" the old sills. Definatly, if you are going to repair the sills, do the whole replacement (all 3 pieces).
Be prepared for a LOT of drilling, grinding, test fitting, and lots more. It really would probably be cheaper to hold out for a rust free car (especially if you also have to buy the welding equipment) than to try to save this one.
It would be a little different if if you already had the welding stuff and had done this kind of thing before.
But I have to admit, this is a do as I say and not as I do, beacause I'm the biggest sucker for any rotted-out-but-dirt-cheap LBC.
Best of luck in whatever you decide Guv'na

 

[ROADSTR6]

The sill is really four pieces: inner, vertical, outer, and castle section. I agree with Banjo. I have never seen inner sills rust out, leaving the other sections completely intact. Your outers are probably a patch job. Plan on replacing all the pieces. If one side is bad, chances are the other is too. Whether or not to dive into a project like this is up to you. I think you should at least know what you're up against before you start. You CAN do it! It's not rocket science. As for weld quality, I'll probably get flamed for saying this, but you're not going to get any really deep penetrating welds doing this job anyway. You're dealing with thin 20 gauge and less material. Doing this job with my Hobart 135 machine on the lowest setting and moderate wire speed, I still get some burn through from time to time. In a unibody car, the structural members work together to spread the load. There isn't a huge amount of stress on any one part that would justify special attention to making superb welds. Honestly, look at how it was welded from the factory! Lots of little tacks. You can pop one of these with a screwdriver! Bottom line, I wouldn't get too carried away with weld quality. That is not to say that slapping a blob of metal on two parts to join them is okay either. There is a happy medium. Find that and you'll be okay. Good luck!

 

[Scott_Hower]

[ QUOTE ]
As for weld quality, I'll probably get flamed for saying this, but you're not going to get any really deep penetrating welds doing this job anyway. You're dealing with thin 20 gauge and less material. Doing this job with my Hobart 135 machine on the lowest setting and moderate wire speed, I still get some burn through from time to time. In a unibody car, the structural members work together to spread the load. There isn't a huge amount of stress on any one part that would justify special attention to making superb welds.

[/ QUOTE ]

I agree with this. The hardest part of a sill replacement is panel alignment. You will spend hours getting the parts to fit right. If you have above average mechanical skills and alot of patience, you'll be fine.

I took a class at my local community college to learn how to weld (MIG and oxy/acetylene). When it came time to weld the panels for good, I rented a Hobart Handler 135 MIG from my local tool rental place for the weekend (about $65).

The vast majority of the panels are 20 gauge steel. The only really thick piece is the inner sill. It's really not that difficult - too much heat/wire feed and you'll blow right through. Too little and your weld beat sits on top.

 

[ROADSTR6]

Whew!!! I've got at least one person on my side here. Thanks for your input, Scott. I was afraid I'd get banned from this forum forever!