Frame Sag

[Csarneson]

So 2.5 years ago Andy was going to investigate the foam-filled frame option. Has anybody actually tried this yet? Conceptually it sounds promising as long as a completely impermeable foam is used.

Chris

 

[RAC68]

Hi Chris,

A while back I did quite a bit of investigation on the potential of filling key frame components with a special foam and posted my thoughts. A little while after, I had some health problems to address and never followed through. There are quite a number of benefits to filling our frames with foam, however, a major issue needed to be accepted is the extra work that would be needed to clear the foam as part of a future frame repair if needed (i.e. damage caused by an accident). I found that the issue of trapped water accelerating frame deterioration can be addressed without much difficulty and the foam would bond and seep deep into the inner frame rust to create a bond that would definitely strengthen the box. However, properly filling the frame would require access to the full access to the frame sections to be addressed and, since my car is completely finished, would require I do a major disassembly. One day when I finally decide to rebuild my motor I will address this again and probably do it.

Good luck,

Ray (64BJ8P1)

 

[Brinkerhoff]

I actually saw this car in person last summer ( drive by , open garage). The owner was showing me the car and when I saw the doors couldn't be opened on it because there is no gap at all, I remembered that this was the car BNW had in his shop. Oddly enough , its a decent car and nothing wrong with the frame , the inner and outer sills were replaced and the car painted before they fit it together. He has to jack the car up in the center to open the door gap enough to open the doors !

 

[Healey Nut]

. Oddly enough , its a decent car and nothing wrong with the frame . He has to jack the car up in the center to open the door gap enough to open the doors !

Think about what you have written here . How can there be nothing wrong with the frame if he needs to jack it in the middle creating a fulcrum flex point to open up the door gaps to allow the doors to open . The frame is done period .

 

[Brinkerhoff]

Healey Nut, any one of these cars will open up when you jack it up in the middle unless you have one of Martin's chassis.

 

[Brinkerhoff]

Its part of the aging as the inner and outer sill loses strength , the door gaps close in the rear as the frame relaxes. It could've been ok if the repairs were done with the center of the car raised slightly.

 

[Healey Nut]

Healey Nut, any one of these cars will open up when you jack it up in the middle unless you have one of Martin's chassis.

Sorry couldn't disagree more . I have an original repaired (correctly) not reinforced not foam filled etc chassis and it does not sag and the door gaps are perfect . Also when mine was restored all the body was test fitted without driveline just a bare shell . it was all removed painted and I rebuilt it and put the drive line in . Refitted all the doors wings etc no problems . If it sags then it wasn't repaired correctly ....

 

[RAC68]

It is not unusual to find door gaps disappear if the outer sills and dog legs are badly deteriorated. Also, if a badly performed repair was done and the car was lifted at its suspension points or set on its wheels when the sills were removed, the loss of sill support could also allow the car to sag at its center. In a situation where this has taken place, I would suspect that the sills would need to be relieved and repositioned for correct door spacing before reinstalling the sills. These installations require door bracing and support at the center of the car to reestablish proper spacing (as the Healey Nut suggested) when disassembled and before reassembling of these important support components.

Additionally, since these repairs may have been performed incorrectly and inconsistently between sides, I would expect iit could easily change suspension points with one side slightly higher then the other.

Ray (64BJ8P1)

 

[Pierre]

Hi,
You have a picture of this type of chassis ? What is the width of the metal used to make the chassis ? Thanks

 

[drambuie]

And this is the reason I own only solid original factory built British sport cars! Yes, they are hard to find, but worth the hunt!

 

[Keoke]

Healey Nut, any one of these cars will open up when you jack it up in the middle unless you have one of Martin's chassis.

the inner and outer sills were replaced and the car painted before they fit it together. This usually causes this problem.

 

[bob hughes]

the inner and outer sills were replaced and the car painted before they fit it together. This usually causes this problem.

I have had one of my cars in the past pertly rebuilt by John Chatham, the floor, and wings were gone and the sills. John chained the car down to the floor - front and back and jacked it up in the centre to straighten the main rails a tad then put the floor and sills in. He did not cap the frame at that time but I suspect that the frame would have capping pieces welded along the bottom if done now.



Bob

 

[Kobus Brink]

I do agree with the foam flling although I have never filled any chassis with foam. However I have worked with foam on other projects on boats .According to me the correct foam won't soak water. I have run tests with foam with we use on boats with are very light .They do soak water if you keep them submerge for years. The buty about polyurethane is that it adheres to steel. You can also get it in different densities.I have chosen it in a density that expands 2 times. The stifles is the same than pine wood. You can even strengthen it by adding carbon fiber. Because it is close cell it will definitely retard or eliminate rust. What I am still struggling with is how to get it into the chassis .If you are going to leave voids it won't work.Another worry is that if it start expanding it might balloon the chassis. My current strategy is to push it in fast hydraulic with escape holes every 500 mm. According to me you can make it as strong and as ridged as you wish.

F

 

[Jack T]

I talked to someone who said a sagging frame could be fixed by ramming a properly sized channel into the main frame rails after removing the front 'horns'. Sounds drastic, but in theory it should work.