Frame Rail Repair, What I Did

[JCG]

Quick overview on how I repaired my driver’s side frame rail. The previous owner tacked some metal over a huge rust hole and finished it off with bondo. Nice work. I had the front subframe and the pedal box out so it was a good time to fix it along with the floor. I cut out all the rust, leaving as much metal as possible. Lots of debris, acorns and a dried up mouse in there. Ground off all the suface rust, cleaned up with air and a shop vac. Shoved a rag soaked in solvent attached to a coat hanger up into the cavern to neutralize the brake fluid and mouse piss, then followed up with weld through primer. I also had the floor out which made it very accessible. Used to spot weld cutter when possible to remove the floor and not damage the frame rail.

I then made a bookmark shaped piece of relatively thick metal (12 g?), shaped it then slid it into the rail and tacked it into place. Probably not necessary but might add some additional strength. I then made three overlay pieces with card stock, trimming with a sharp razorblade. Taped them together in place with masking tape. When I was happy with the fit, I traced the card stock onto 18g sheet metal and cut them out with a scroll saw. On hind site, I should have used a bit thicker metal for better strength and easier welding. Tacked these pieces together and checked it for fit. Not bad. Made a few adjustments then stitched the pieces together. Drilled out spot weld holes and primed the piece. I then forced it into place using many clamps and a hammer. Filled the holes with spot welds, which required either moving the clamps at each weld or tapping with a hammer to make sure I had a tight connection between the overlay and the original frame rail. A bit messy since I was on my back welding but nothing a grinder can’t clean up.

I primed, painted and undercoated everything…I think it looks pretty good and should be pretty strong. I did some unconventional rust proofing as well. I attached a small hose to a can of white lithium grease (put a red plastic tube that comes with the spray on either end of a length of small diameter hose to act as an extension). I also drilled a few small access holes in the original frame rail and off set a few others in the overlay. I then filled the interstitial space between the overlay and frame rail with grease. I also sprayed lots of grease into the holes at the top of the frame rail (the ones under the brake reservoir that is responsible for the rust in the first place), then plugged them with small rubber stoppers (probably can get them at a good hardware store). I also sprayed copious amounts of grease up into the threaded holes where the subframe bolts up to. I have used lithium grease spray on my boat, trailer and truck to protect against rust and it works well; dries and tends to stick for a long time.

Looks like my pictures are in the wrong order, but you get the idea.

If anyone wants to try it and has questions, let me know and I can elaborate.

[JCG]

(nt)

[JCG]

(nt)

[nbcbird]

It's nice to see some craftsmanship by guys who don't like to take short cuts--good job. Riviera is da best.

[M3M3]

nice work and thanks for taking the time to write it up!

wanna practice on another car? ;-)

[rctid]

just curious but what type of welding were you doing, mig, tig?

[schivvers]

THANK YOU FOR POSTING THIS!!

I'm about to tackle double floor pans etc...been a bit nervous about repairing the frame rails for I'm sure I will find rust. This is something along the lines that I had planned. If you have any more details I would love to hear them. Thing like how you you removed all that farking undercoat? Or, did you use "weld through primer?" and...last but not least...how did you keep the frame rails "located" with out the pan in place anymore?

Or am I over thinking this...that could be.

Cheers

Dave

[Scott Sislane]

looking good Jim!

Scott

[JCG]

I used a mig. I have a Lincoln from Home Depot, can't recall the model but its the 230V one. It works pretty good for my needs but I could use a bit more voltage adjust-ability.

I removed the undercoat (what was left of it) and much of the rust with a couple types of stainless wire wheels, the kind you attach to a 4.5 inch grinder. That and grinding wheels. I use the grinder for just about everything; get the thin cutting wheels, grinding wheels, wire wheels and also the plastic disks with multiple sand paper patches....that worked well too for removing old paint, rust and rubber. Maybe this picture will show what I mean. http://www.instructables.com/files/deriv/FRF/IOMM/F9AZJK09/FRFIOMMF9AZJK09.MEDIUM.jpg

I didn't have a problem with the frame rail coming loose. First, I blocked up the car in several places to keep it from twisting. My front end was out and I had the engine blocked up as well to remove as much weight as possible. Turns out, the rail rust was mostly at the curved point; it was pretty solid where it runs under the floor. The tail end of the rail is welded fairly well to the back side of the drivers floor pan, so I left this connection in place and I think this kept everything lined up and true. Hell, the frame could be totally racked but I'll never put it on a frame jig to find out. Block the heck out of the car before you do any cutting and you should be fine. Take lots of notes and measurements as well. I reused the gas pedal mount that is welded to the floor....make sure you take several measurements from various points to ensure you put it back exactly in the right place on the new floor. I didn't buy a floor, I "made" my own. I'm not too particular with authenticity, just strength. Seam sealer and undercoater certainly makes my work look better.

As far as rust proofing paints, I didn't do a great job with that. I forgot to mention that I used POR15 in places. There was a hole in the side of the inner rocker. I shoved POR15 in there with a rag and wire. I think these paints are hard to work with when you eventually weld over them. Toxic smoke and after the heat, the paint probably doesn't protect anymore. so yes, I did use weld thru primer where I could but relied on grease, seam sealer and drain holes to protect against future rust.

Another thing I should mention is that I am lucky to have all my fingers and both eyes. My car was only a couple feet off the ground, so it was really tight for grinding and welding. Those wire wheels are so friggen dangerous; god forbid you drop the tool on you while under the car. Yes, I wear all the safety stuff but I think I still have welding spark scars and POR 15 freckles. Be careful.

Dave et al, don't hesitate to ask me questions, I'm no expert but I'll try to help where I can.

[TobyB]

What'll really extend the future life of the repair

(if this car gets wet)

is to now spray protectant INTO your repair.

3M rustfighter, Waxoyl, wurth, even lots of old engine oil.

Makes a huge difference, in my experience.

Nice work.

t

[JCG]

Like minds..... That's just what I did; emptied a can of white lithium grease between then sheet metal and other hard to reach places. It will be there for the next 40 years.

[Guest Anonymous]

I need someone who can do this work - any suggections?

[williamggruff]

Well, since you haven't told us where you're located, you can mail your car to Sports Car Restorations in Connecticut. The owner, Matt McGinn, has a sterling reputation.

[Scott Sislane]

Well, since you haven't told us where you're located, you can mail your car to Sports Car Restorations in Connecticut. The owner, Matt McGinn, has a sterling reputation.

Gloucester, MA....So Jim, how's the 02??