Frame Restoration

[TimR]

Steve, Thanks for all the great info, photos, and methods used in repairing a frame. When you cut an original frame apart have you seen any of the tubes that are of double wall construction, meaning one tube inside the outer one? Seem like I heard this somewhere that the factory did that for added strength on the backbone and downtubes. I have never cut up a frame but can see where nerves would be on edge.
Tim

[Steve Little]

Hi Tim. I will post some pictures of the internal stiffener tubes shortly.
Cory, Jonathon and Tim, thanks for the praise but this idea really belongs to the young bloke who works with me, Steve Jacobson (he,s fourty and I'm 54 so I get to call him young bloke)
Some of you may have had some dealings with him via emails while buying parts or frames.
This is his idea. If it were left up to me, we would still be plowing into the next job, cutting up junk chopper frames and turning them into frames for restorations.
I think the old saying is "turning a sow's ear into a silk purse"
I am not sure how wordy to be in the descriptions of the work that we are describing, but I will ease my way into it.
Give us a yell if it seems a little slow
Iv'e got some office work to do now, but will post some more pictures shortly.

[Steve Little]

Cleaning out the Sidecar lugs.

Hi
The following procedure, relates to cleaning out the tubing of electrode welded, side car lugs.
The sidecar lugs that have electrode welding, have a ½ inch plug weld on the outside edge, as well as the circumferential weld to the tubing.

First step is to guess the centre of the plug weld and centre punch it.
Depending how much beer ration the welder had on the day might be why they vary in size..joking.
On average, the Harley welds were ok, and it was not the welding that broke.
I use a centre drill to start and then work my way up through the drills to ½ inch.
I jump 1/8” inch per drill until ½ inch.
When you have completed the ½ inch drill, have a look in the hole and look for a separation line. The dark line should be easy to spot in the freshly drilled steel. If the drill missed the edge, get out the die grinder and grind away until you find the edge. If any of the plug weld is still holding the tube you need to free it.

Original forgings where machined so that the tubes are a slip fit.
The tubes have straight knurling with a .001 stand-up over the tube diam.
The knurling usually (not always) extends past the end of the forged part. The knurling has two jobs to play.
Firstly, it gives the molten braze, a channel to run down to ensure a deep braze joint in the socket.
The other job of the knurling is to lock the tube to the forging when it cools down, after welding.
If you have ever done any frame work you will know that it does a pretty good job of it.

For those of you without knowledge of this, the heat generated by welding or brazing heats the forgings which in turn expands them both.
After welding/brazing, the out side of the part cools faster, and shrinks onto the tube which locks the knurling of the tube into the inside surface of the socket in the forging.
When we manufacture our frames, or when we do frame restoration work, all of our welds (whether electrode or braze) are left to air cool while the frame is still locked in the jig.

Harley Davidson had a different technique.
All the early Big Twin frames from 1936 through to late 1944-early 1945 (brazed seat post models) where quenched in warm water from brazing heat and left to soak for one hour to draw to C20-C30 Rockwell.

The frames from 1945 through 1947 had a different technique.
The axle carriers and the neck section were quenched in warm water from brazing heat and then the whole frame was placed in warm water for 1 hour to draw to C20-C30 Rockwell.

Chris Haynes has a marvellous picture that shows the frame brazing department in 1939.
In the background of the shot you can see one of the quenching baths steaming away.

I have been asked many times (at Davenport swap meet and via emails) what electrode we use for welding.
I can tell you that Harley Davidson used #7 Lincoln welding rods.

I have experimented with electrode welding over the years, to get the closest appearance to original welding.
Harley Davison welding from the 30’s through the 50’s on the rigid frames had a very flat style weld.
In order to copy that welding style set my Miller Dialarc HY CY50 welder to the following: for all electrode welding on Harley frames:
Straight polarity- 45-180 DC volts 72 amps
No point me telling you the rod make because they are Australian made but they are GP (general purpose) 2.5 mm rods.
1945-46 frame pictures 047.JPG1945-46 frame pictures 051.JPG1945-46 frame pictures 044.JPG1945-46 frame restoration 016.JPG

[Steve Little]

1945-46 frame restoration 001.JPG
Tim. Heres the stiffener tubes you where asking about.
You might be able to see the brazed in stiffener sleeves. They start at the end of the tube in the sidecar lug and go just past the front engine mount...on the back side of the engine mount.
Harley put these on both sides at the front and they also put them on the rear of the left/ drive side tube.
The rear stiffener is longer and finishes just after the big bend.
I should mention that Harley only put stiffeners tubes in the 1/16 wall tubes.
When they progressed to 1/8'' wall tube in 1952 there was no need for the extra work.

[Steve Little]

The previous picture also shows that I have used the slitting blade in the grinder and cut the circumferential weld away from the tube and forging.
I then heat the end of the sidecar lug and tube. You can see the heat blueing on the end. This helps to free up the two parts. The heating and cooling seems to tear any thin welding missed by the slitting blade.
I then give it a light whack with a hammer on the end of the tube.
This slightly drives it up into the socket, but at the same time shows me that it is ready to come out.
When your sure the tube will move with a light tap of a hammer, then it is time to cut the tube flush with the end of the sidecar lug. Grind the weld until you can see the separation line.

Then set your self up with a light hammer. A “sharp” ¼ inch cold chisel, and a lit oxy set with a cutting tip for heating.
Run some heat into the first layer of stiffener tube then quickly try to tap the cold chisel under the edge if the split that runs up into the sidecar lug. Heat and tap until it curls up inside.
When you have the two layers of stiffener out….should take about 5 to 10 minutes a side… you will be down to the main tubing.
I use a die grinder with a ¼ dremel.
I grind a groove along the inside of the tube, on the opposite side from the hole that was the plug weld.
It takes me about 5 minutes a side to brake through the full length of the tube inside the sidecar lug. You will see a dark line when you
Then I use the 1/4 inch (sharp) cold chisel again and tap it under the edge of the groove. Having the lit, oxy on the side fitted with a cutting tip helps to quickly heat the tube and then lightly drive the cold chisel under the edge. Keep heating and lightly curling the tube up with light hits on the cold chisel.
At this stage there is no need to put any heat into the sidecar lug…just the tube.
Small hammer, light hits, well supported frame, and it will curl up inside the socket. Then a small set of vise grips will get it out.

HEALTH WARNING
Don’t breath in the smoke from any frame work. Heating, grinding, welding,brazing.
For the uninitiated, you will most likely over heat the braze.
When you do, a white smoke will rise off the weld….dont breath it in… brazing flux has cadmium and other toxic chemicals in it. Not meant for frail little human bodies.
Also, the frames where Parkerised and I don’t think the fumes from this, are good for you.

When trades people or shops ring here, they ask for Old Steve or young Steve.
Young Steve wears a face mask when he is brazing and working on these frames.
He is doing more of the work for me now…under iron fisted scrutiny, of course.

We have a large exhaust system for the factory. This helps evacuate the fumes floating around the shop when we are brazing or oxy cutting/heating parts of a frame. But it does not stop the fumes from being inhaled when we are concentrating over a job. Wear a mask.

[Steve Little]

Keep the frame supported while you work or you will find cracks that were not there before

[Steve Little]

Next job is to clean the tubes at the back of the frame.
On this job I have decided to use the remaining part of the lower tube at the back section of the frame.
We will make a sleeve to go inside the tubes.
A rule of thumb that I use is that the wall of a sleeve should not be any thicker than the wall of the parent tube.
We have repaired so many frames that have come from the U.S. that have solid slugs inside a repair.
Generally a crack has appeared at the end of the solid slug repair. A solid slug will not move with the rest of the frame.
1945-46 frame pictures 053.JPG
1945-46 frame pictures 055.JPG

[Steve Little]

Hi.
I was just re-reading the thread to see if it was in order and made sense, and I looked at these pictures. I thought I should mention: that regardless of whether it is a 4 inch, 5 inch or 9 inch grinder, if you are cutting through a frame tube, you should make sure you have your feet firmly set apart, your elbows folded in close to your body, and holding onto that grinder with grim determination.
Quite often a modified, or crashed frame will have a lot of stress in the tubes.
You can bet your bottom dollar that the time you dont brace yourself, it will be the time that the tube will pinch on the cutting blade.
I have broken many 5 inch slitting blades and one 9 inch cutting blade. The 9 inch incident was memorable and the vibration, intense. A bit of sphincture clamping going on I can tell you. The small slitting blades will cut a finger off as quick as a buzz saw
If you are not holding on to a grinder properly chances are it will be the time that it pinches the blade.

[Steve Little]

Time for re-assembly

Check the tubes will fit into the sidecar lugs. The left side slipped in. The right side had shrunk so I used the die grinder with the 1/4 inch tool that was still in it. Then polised it with our self made tool. 1/4- 6mm rod with a slit in the end. 12 inch -300mm of emery tape. fit it in the slot, wind it tightly around the shaft and way you go. fit tube, polish a bit more, fit tube, polish a bit more, until it slides in.
If you dont take the time to get it right, it will be a bugger to work with. You need to be able to slide this tube in and roll it left to right with ease.
Now that the weld has been ground off and linished, we will shorten the rear tubes a little more.
The reason for the left side is that we like to have the join away from the inner primary relief pressing. We will cut the tube back about an inch. This will place it in the middle of the rear trans cross braces.

[Steve Little]

Some of the arsenal you will need when cleaning tubing out of a forging

[Steve Little]

A quick trip through our store. This lot should be right for the job

[Steve Little]

I fit and weld the brake cross over tube to the rear engine mount before it is fitted to the seatpost.
Slide the mandrol through the left side of the rear engine mount, and then through the brake cross over tube.
Sit the rear engine mount up on a thick block, then a quick line up and adjustment for the correct angle of the grease nipple hole, and whack her in with a nylon mallet.

Now its ready for welding.
I leave the mandrol in the assembly while I tack and weld it.
We manufacture these mandrols to the correct total length This means from the end of the brake cross over tube to the left side of the rear engine mount.

This will be the last post until Monday morning.
It is Friday afternoon here and I have a few things to do this afternoon and I,m working on my 37 over the weekend.
I can tell you that the frame looks marvelous, but you will have to wait, and work through the process in the posts in this forum.
If you have any questions feel free to ask or contribute.

Regards Steve Little
Race Frame Engineering
Australia

[c.o.]

This thread just keeps getting better and better. Thanks to both "Old Steve" and "Young Steve"!!!

[hdkh1947]

I just couldn't help but to add this after you posted what you posted! I found this listed on ebay right after looking at the thread with a starting price of 495.00 $(KGrHqMOKpQE7IwNOMyQBPZ8n(fhZQ~~60_57.jpg Jonathan

Except for the front engine mount, the rest of this section is junk.

We will cut the front engine mount away this frame section and clean out the tube. Then it will be set up in the mill and we will lightly cut the damage to the decks so that it can be bolted to the jig when we start to re-asemble the frame.

I had a laugh.
I was standing there getting my energy back and looking at this junk section on the floor, and the young guy who works with me pipes up and says, "Ive seen some guys on ebay who would list this as a good start to a frame restoration"

[Steve Little]

Hi.
I received a question from a guy about why I didn’t use the oil tank mount and the running board lugs off the frame section.
These pictures will show that at some stage, someone has taken the running boards off and re-assembled them back on the bike, forgetting to replace the thick washers on top of the running board lug.
This dammage to the running board lug is the end result. Both sides have worn, well under the original machined pad.

The thick washer is designed as a "consumable" in manufacturing terms.
It is supposed to be the part that takes the wear and be replaced when out of service.

They are both junk.