Frame Restoration

[Steve Little]

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

[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]

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]

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]

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.

[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

[hdkh1947]

Thanks Steve for the awesome thread! Wish I was there to help and LEARN! Thanks for sharing your knowledge.
Jonathan

[c.o.]

I'm following this thread with great interest Steve. Thank-you for taking us through this job.

[Steve Little]

These frames are very fragile in this state.
If it drops off your work bench in this state, you can create hours of needless work.
I place a mandrol through the sidecar lugs and have a pipe spacer between them to hold lugs in the correct postion. It also gives strength/support to the front of the frame.
For the same reason I have deliberatly left the cheap Tiawan toolbox bracket in place to give a bit of bracing to the rear end.
I also put a brace between the axle carriers for support.
This frame is 1945-early 46 and the seat post area and the sidecar lugs are electrode welded.
Frames from 1945-1947 are not as delicate as the 1936-1944 frames.
The earlier frames (with the brazed seatpost assembly) are more prone to cracking when in this dissasembled state.
A good practice is to always have the frame, well supported when working on it. Any year.

Although the pictures are not in sequence....they just put themselves where they damn well liked... I think you will be able to work out which picture I will be explaining.
In the pictures I have ground down the seat post tube until it got to the crack. You can see that the welder failed in his attempt at penatration. The next shot is ground down to the original HD weld. Hopefully you can see the sepperation line in the bright finnish of the steel. This the guide you are aiming for. Then I used a drift and knocked out the brass bush. Then ground the factory weld off the top of the seatpost cluster and drift out the remaining seat post material.
Even though these posts have been added over a day and half, the real time up to this stage is about 3 hours work.

[Steve Little]

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]

For those of you who are a little delicate or squeemish, now might be a good time to turn away.

[Steve Little]

Hi Tim.
We had a pretty good thread on this issue a couple of years ago.
One of the contributors thought he had seen a document that instructed dealers to bend frames with a sledge hammer and hard wood. But no one was able to come up with said document.
Personally I have never seen a frame that looked like it had been altered by a dealer.
It was probably a urban myth, or maybe some of the old timers of the past were trying to make rational sense of the true factory "Bent" frame was like it is.
Harley made two changes in 1940. The "foreward sweep" springer that was produced from 1936 through the 1940 production run. It was changed to a True inline springer for the 1941 production run. The other change was the heavier 16 inch wheel. I believe the combination of these two changes culminated in severe handling problems at high speed. The factory had to make a quick change to the frame to increase stability and slow down the steering. This was achieved by altering the neck angle from 25 degrees to 28 degrees by way of pre-bent backbone and down tubes. This meant that early 1941 "Bent style" production frames had pre bent tubes before assembly. The backbone of that perticular frame would have been cold forged. We do similar cold forge tube press here, for the rear downtubes of a swing arm frame.
Regards Steve

[Robert Luland]

Because the rest of the frame was locked down in a frame table to make sure it didn't move.

[TimR]

Steve, I to had an impact with a solid object (very large rock) with my 1942 UL and the frame suffered similar damages. The backbone and intermediate backbone bent up, both front down tubes bent out. Upper motor mount broke. Both tubes broke below the sidecar loops. Seat post tube cracked. I rode the bike before dismantling, 45 MPH hands off the bars and it tracked straight down the road. So much for people using that as a guide to prove that they have a straight frame. With the way the frame bent I have a hard time understanding how the MoCo bent the 1940-41 frames without disturbing the rest of the frame.

DSCN0508.jpg

[Robert Luland]

No, the pictures still have to be entered at the post. Bob L