Soliciting opinions, advice for frame repair

[crj7driver]

I am in the process of resurrecting my frame to some level of safety and rigidity. The frame is solid except for the trailing arm attachment points and one area in the waist. When I cut one of the trailing arms out, the area where the trailing arm meets the center of the frame is heavily pitted. It appears structurally sound (i.e. if I take a screwdriver and try and hammer it through the frame it does not give or dent).

So the question is, do I

A. Leave it alone and just clean the rust up
B. Cut the section out and weld in a patch piece
C. Weld a doubling plate over the area after I clean
it up
D. Do B & C
E. Something else?

Thanks for any and all help. I just want to do it the best way possible as long as I have the frame torn apart.

 

[Brosky]

I don't know your budget or final plans for the car, but it looks as though you're into a serious restoration. I would love to do a frame off on a car one day (not my original TR6, at least for another 10-20 years), but perhaps on a second car.

If I had any concerns about the main and most important structural item on the car, I would go with a Ratco frame, as long as:

1. I was that far into it
2. I could afford it, because I have no idea what they cost, but man, they do look good with the suspension upgrades in the rear and the new sway bars.

Then you would know, from the ground up, that you are totally solid.

https://www.rat-co.com/frame%20fin.html Check out the informational handbook and pics inside.

 

[Banjo]

I would sand blast it, treat it with some kind of weld through primer, or anti-rust chemical of choice then go on repairing the frame.
I feel that cutting and welding out that piece would induce more rust faster than what is already there, and welding in a doubling plate is engineering in a rust factory between the two layers of metal. DO NOT double layer it, please, you should have seen the inbetween when I peeled the repair panals off the quarters of my dads MG that they had just slapped over the old ones, and think of that plate on your frame where that rail met the waist. I bet it had a fair amount of rust under it.
If wailing on it with a hammer and chisel shows it to be fairly sound, I'd say it's good enough to work with.
Best of luck.

 

[Alan_Myers]

Hi,

Paul's Ratco frame suggestion would be the ultimate solution! But, from the photos, the frame looks pretty solid (compared to some others!), assuming it has little other repair needed, and measures to be straight and true, too.

It's a little hard to tell even with very close photos you provided, just how solid the remaining metal is. I'd err on the side of caution. To be safe, if you have the materials and welding skills, IMHO the best approach would be to cut out the rusted area and replace it with solid, new metal.

The new section could have some sort of flanged ends on it, that fit into the old portion of the frame tightly, giving a good, broad area to weld up tight. It might also be a useful to double up some of the area with "flitch plates" or similar type of reinforcement.

Do a your welding a little at a time, swithcing from side to side, to keep from overheating and prevent warping.

I don't know if your goal is to keep the frame as stock looking as possible, or if you want to upgrade it in some ways. If the latter, I suggest you get a copy of Roger Williams' "Improving Triumph TR250, 5 and 6" for a lot of different IRS frame reinforcement/improvement ideas.

There might be other articles on the subject, too. Some years ago Grassroots Motorsports ran a great article on reinforcing and strengthening the earlier ladder chassis used under TR2/3/4. Maybe you can locate something similar for the IRS cars.

One idea I've seen used on both cars is to install large skid plates under the diamond shaped area (either side of the central tunnel, i.e. under the seats) that would certainly strengthen/stiffen the frame substantially, as well as protect the car's occupants! The downside is additional weight and some difficulty accessing things like brake and fuel lines that run through that area.

/ubbthreads/images/graemlins/cheers.gif

 

[Banjo]

I bow to Alan. I believe his advice is far sounder than mine. Listen to him.

 

[PeterK]

By the picture alone, it looks reasonably solid, surface pitting is OK. But best to tell by spinning a scotchbrite over the area to test. If the pits clean up to shiny metal quickly, the rust is not bad, but if it doesn't lighten up and is still rusty in the pits, then you must section and replace per Alan's instructions. Either way, I'd use phosphoric acid (Eastwood metal prep) on the rust spots to stop it from advancing. Make sure to spray a protectant inside the channels too.

 

[crj7driver]

Thank you for all of the input. I will see how easily the rust (in the pits) cleans up and go from there.

 

[TR674]

crj7driver
I emailed the files to you. Just rename with .jpeg to view.
Hope this is what you are looking for.
Regards
Craig

 

[Alan_Myers]

[ QUOTE ]
I believe his advice is far sounder than mine. Listen to him.

[/ QUOTE ]

Not necessarily!

You make a really good point about layering over old rust or creating a pocket with multiple layers of metal, that will retain moisture and give new rust an ideal hiding place. I should have gone a bit further in my explanation there.

Flitch plates, gusseting or any type of added plating needs to be installed well to avoid any openings that moisture can find its way into. There can't be any rust under it to start with. Even the slimmest joint will allow moisture inside. Use a weld-through primer wherever you can, but that's only a partial answer.

To avoid problems in years to come, completely edge weld and/or use seam sealer to close up even the tightest gaps. Powdercoating and/or paint can help seal things up, too.

But, keep in mind that you can't oven-cure powdercoating if seam sealer was used. Body solder or "leading" is another method of sealing things up pretty thoroughly, some types of body solder can even be used under powdercoating that's cured carefully.

Also, a final spraying of the frame and chassis inside and out with Waxoyl or a similar product can help. Triumph certainly did a lot of this at the factory on my TR4 and only recently did I remove the last traces, still heavily caked all around the parking brake mechanism and on the top side of the diff housing for example. Triumph might only have intended this to preserve their cars during overseas shipment, but some of it lasted and remained effective 40+ years! Parts sealed underneath the heavy Waxoyl coating (more like caking actually) were still "like new" when it was finally removed.

It also didn't hurt (in terms of preserving the car... although certainly not ecological responsibility) that a TR4's open breather crankcase tends to spew engine oil mist all over the bottom of the car. That's not applicable to TR4A and later, though, with their closed crankcase breather circuits.

/ubbthreads/images/graemlins/cheers.gif

 

[michalotti_tr]

[ QUOTE ]
It also didn't hurt (in terms of preserving the car... although certainly not ecological responsibility) that a TR4's open breather crankcase tends to spew engine oil mist all over the bottom of the car. That's not applicable to TR4A and later, though, with their closed crankcase breather circuits.

[/ QUOTE ]

Not that it always helps - My TR4A was fitted with an SAH modified engine to include the older style breather tube, and my frame is toast. Next on my list of aquistions is a replacement - would love to get one of the Ratco frames(I was one of the first to speak to him about going into the business), but the price is twice what I paid for the entire car! Of course, the used frames I've been able to look at so far aren't much better than what I've got now, so I may go ahead and bite the bullet. Whichever frame I do get, I am going to foam-fill the interior like Ratco offers with their's - the reason being my current frame has rusted from the inside out /ubbthreads/images/graemlins/eek.gif