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ideas on how to fix dents on frame

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bighealeysource

bighealeysource

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Hey y'all,
Okay, any ideas on how to best repair the multitude of small dents on the horizontal surface on my 100M's frame rails ?
Primarily in the middle of the frame close to the crucifix area. Vertical sides are fine, just the bottom. Have no idea how they got there in one general area but this car was raced extensively in the late 50's and early 60's. None are huge, really just cosmetic but other than getting a new frame - which I am not interested in doing- thought there might be some suggestions on how to repair. I know, why bother but if I can fix the worst of them would be nice to clean them up.
Thanks,
Mike
 
Sounds like jacking dents? One idea, maybe not a good one, would be to drill and tap holes and use a slide hammer attached to a bolt in the tapped holes to hammer out the dents. Then you could weld the holes shut. Another idea, would be to use body filler.
 
You must be careful or you can rip the seams [center ribs] apart, as the frame rails are made up of two C shaped channels welded together at the ribs.
 
Many years ago, when I was one of those "artichokes" in life (architects to you), I do recall learning how steel's strength design is always best in tension, more so than in compression like concrete (concrete by contrast, is poor in tension--that's why you see re-bars in concrete, to make up the tensile strength missing in concrete). The subject of dynamics like bridge design is another subject so "I'm out".

Back to classroom 101 statics, and I have to look at the Healey frame as one of static design even though I bet it could fall under dynamics as well because the car is in motion, too. I'll leave that up to the engineers to argue.

But if it were me, rule number one: Never compromise steel's strongest area of design which in this case, would be the bottom flange which acts in resisting moment forces (twisting, buckling). The webs of the box beam resist shear forces. How bad are these dents? If it's a cosmetic issue, I wouldn't drill any holes. I would bondo it and live with it.

If these dents are nasty and forcing the webs to actually become deformed, one approach I would use is to drill a small hole on the top flange, place a steel plate firmly at the underside of the bottom flange in need, and hammer a durablee steel dowel through the opening to the affected area. Kind of acting like a jeweler do fancy chaise work.

Rule number two. ALWAYS drill along the neutral axis of any web or flange. That is, the center of any web height. Example, if you have a 4" high web, then you drill at the center which will be at the 2" diameter on center mark. These areas yield the least amount of stress (you'll sometimes see drilled holes on wooden beams for the snaking through of electrical BX wires). If not, sue your electrical contractor, immediately!

Paul

PS - BTW, I will define the web of any steel beam as the vertical section which connects one or two flanges which are horizontal (basic box beam has two flanges, and of course, two webs, usually). So whereever the two webs are along the flange, then drill center (neutral axis) and inbetween the two webs. If the box beam is a composite design (IE. two box beam sandwiched together). them the same rule applies--always inbetween two webs or not center of the composite design.

Any engineers out there want to argue? I am just a former artichoke. I am all ears here!
 
richberman said:
How about one of these?
https://www.eastwood.com/stud-welder-dent-pulling-system.html
Same idea as TimK but no holes at the end to fill.

rich
Click to expand...
The Healey frame metal is thick er than typical body panels. I'm not sure that the weld-on pins would be strong enough to pull the frame dents out.

I will agree with pkmh that drilling holes in the bottom will weaken the frame (and I'm an engineer). I don't like the idea of drilling holes in the top, though. There's just too much stuff in the way.

I also don't know how well filler would last.

I'm with Rick.
 
Lead them in??????Not sure if this is still available??

Pete
 
You are correct, the type of puller used to pull fender dents with weld pins will not produce enough force to pull the steel frame rail. I 've taken a 3/8" threaded rod about 36" long and welded it to the seam of the rail on both sides with the mig welder. Then taken the bell from my axle slide hammer ( about 10 lb.) and slid it on to the threaded rod , then put a large flat washer and a nut on to the rod. With the weld still hot , pull smartly like you were pulling a hub off an axle. Your weld needs to penetrate both the seam and the rod. If you are good at welding, the threaded rod will pull off the frame after one or two pulls ( without damaging the seam) as it pulls the dent out. If you over pull it , whack it back with a big hammer and a block of wood. If the damage flares into the side of the rail , as you slide with one hand , hammer in with a flat body hammer. Metal finish as you are capable of. A little finishing plastic will stick just like on a fender. Dress the weld off the rod with your Makita grinder to prep it for the next area. Time consuming, buy hey , in for a penney in for a pound ! I fixed quite a few areas on my BT7 chassis and they are still undetectable after 10 yrs. the chassis is painted with a basecoat /clear. Kevin
 
John Turney said:
richberman said:
How about one of these?
https://www.eastwood.com/stud-welder-dent-pulling-system.html
Same idea as TimK but no holes at the end to fill.

rich
Click to expand...
The Healey frame metal is thick er than typical body panels. I'm not sure that the weld-on pins would be strong enough to pull the frame dents out.

Well they will work just fine if you heat the surrounding metal before you try to pull it out.

I will agree with pkmh that drilling holes in the bottom will weaken the frame (and I'm an engineer).

Naa it will be ok after you fill the hole and lead it over


I don't like the idea of drilling holes in the top, though. There's just too much stuff in the way.

I also don't know how well filler would last.
Nope it will eventually fail

I'm with Rick.
Click to expand...
 
Mike,

My frame had quite a few of these as well. I did a fix similar to what Kevin mentioned. I used 1/2" all thread, cut a slot in the end so it would fit over the frame seam if that's where the dent was and then tacked it in place. Dilled a 1/2 hole in a 6" or so 2x4, cut relief slot across the 2x4 hole to give the seam a place to go. Then tightened a nut down on top of the 2x4. Worked really well

Barry
 
Hey guys,
Thanks for the advice and suggestions. Think I'm going to take Rick's advice and leave well enough alone ! I could just see me making a minor problem into a major problem. This frame had enough abuse when the car was raced don't need any more from me !
Thanks again,
Mike
 
bighealeysource said:
Hey guys,
Thanks for the advice and suggestions. Think I'm going to take Rick's advice and leave well enough alone ! I could just see me making a minor problem into a major problem. This frame had enough abuse when the car was raced don't need any more from me !
Thanks again,
Mike
Click to expand...

A bit late to respond to this relatively old thread, but this is what I planned on doing in my car that has the same problem, probably due to the use of car jacks.

It is taken from John Loftus' page on his restoration of a BJ7:

https://www.loftusdesign.net/restorationweb/dentpulling1.html

https://www.loftusdesign.net/restorationweb/dentpulling2.html
 
elrey said:
You must be careful or you can rip the seams [center ribs] apart, as the frame rails are made up of two C shaped channels welded together at the ribs.
Click to expand...

+1

Before you start pulling and wacking inspect the inside
I would not stretch the steel another time
If you hate the dents fill them up
Not with bodyfiller, not with lead, but with serveral welds
A thicker frame wont hurt ;-))
Afterwards do protect the inside against rust

Hans
 
No, the seam is the strongest part . Welding the slide hammer bar to it will soften the surrounding metal slightly allowing you to pull the metal out.
 
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