Repair pitted fork tubes?

[squish]

Is it in the swept area or above that, like between the top and bottom triple clamps.

I've not had luck with JB weld.

But what worked ok for me was to pull the forks off the bike.
Clean the tube up real good, then polish it I went from 800 grit gently working the rough area away up to 1500 grit
Used wet with a splash of dishsoap in the water to help keep the grit floating.

The metal polish followed up with some high quality wax.
If you keep up on it then you will only need to hit it with some wax every 6 months or so.

You get a small amount of oil weeping, I just wipe the up after every ride.

But you will have to get the tubes replaced or repaired someday.

I've switched back to running fork gators for this very reason.

[kantuckid]

JB Weld is not the magic goop it is made out to be. I think it is too thick for this job & otherwise just another 2 part epoxy paste among many. The really "good stuff" is sold for industrial purposes for most part. I used epoxies in the 1970's in industry that far surpassed JB Weld & am certain there are even better things today. Off to the garden...

[caponerd]

Originally Posted by Wirespokes

The clear repair with Araldite could be made more 'normal' looking by the addition of aluminum filings, or stainless perhaps.

To clean out the rust and pitted areas, use Naval Jelly.

I've used silver solder to repair pits and dings. Can't even tell where the repair was made.

Silver solder? Wouldn't that require heating the fork tube to near red-hot?

I've silver soldered plenty of jewelry, and it has to reach at least 1200 (softest version used in Jewelry) degrees or hotter depending on the hardness of the solder.

What alloy of silver solder do you use for this?

[Wirespokes]

I don't know which alloy it is - got it at the electronics supply if I recall correctly. Sounds like a jewelry supply would be a good source. Been a while since doing this, but think the propane torch focused on the spot was enough. Of course, with soldering, make sure the rust is all gone and the area is clean.

[svejkovat]

Maybe this is too obvious, but chucking the tube up in a lathe would make the process of wet sand much quicker and much more precise.

[Xcuvator]

Originally Posted by caponerd

Silver solder? Wouldn't that require heating the fork tube to near red-hot?

I've silver soldered plenty of jewelry, and it has to reach at least 1200 (softest version used in Jewelry) degrees or hotter depending on the hardness of the solder.

What alloy of silver solder do you use for this?

I have a hard time visualizing the process too. I guess I'll have to WS do a demonstration sometime

[caponerd]

Originally Posted by Wirespokes

I don't know which alloy it is - got it at the electronics supply if I recall correctly. Sounds like a jewelry supply would be a good source. Been a while since doing this, but think the propane torch focused on the spot was enough. Of course, with soldering, make sure the rust is all gone and the area is clean.

If you used a propane torch to do it, I'm guessing that this is a very soft alloy that melts at well below the 1200 degrees fahrenhiet of the softest jewelry solder. A propane torch couldn't generate the heat required for a mass of metal the size of a fork tube using true silver solder.
The other tip-off, of course being that you got it at an electronics supply. This may well be one of the harder alloys of lead/tin based solder, possibly with some silver in it.

[kantuckid]

Yes, there are plenty of soft solders(not true hard-"silver solders" that have silver in them) used for electronics and Brownell's Gunsmithing & TSC also sells a solder like that for general repairs -they all melt ~400+ degF the lowest temp I could find for true silver solders-"hard solders" is in the 1100deg range. There is a guy on ebay that mixes fluxes for resale and also sells various solders and in consulting him I asked for the lowest temp he knew of & thats it. I also have done jewelry work and even what are called the "easy" gold & silver solders will not be done with a propane torch, whereas the silver content soft solders will be no problem. MAPP gas will do the hard soldering jobs from a small can , as will various other gases. My concern going in was- IF?- the 1100 to 1200 degrees will pop the chrome. I lean toward epoxy as a cheapo solution. I did find a hrad chrome place near me and have a question out to them if they do small jobs as many places do not. Actually I see no reason the soft solders will not work( and last a long time) if you can get them to stick in the pits.

[Xcuvator]

The other problem with the hard solders would be warping the tube. Even with the soft solder, I think I would try to preheat the whole tube and keep it lying flat..

[PSchrauber]

FWIN / FYI theses low temp. solders need a rough surface to cling to the applied material, like Lumiweld for example. How will you get the places on the stanchions rough that have to be repaired without doing more damage as you already have?

Befor you get the experience about the meaning: a poor man pays twice, why not ask a hard chrome company if they could give your stanchions a new coat of chrome?

I know there is the route to Canossa but there is always the route back too!

I had the same issue and mine where bend too! Now they are straight, and shiny everywhere. Another good reason to do so is wear at the lower fork tubes that work as guide bushing for the stanchions. You can compensate the wear inside the lower fork tubes by adding some chrome material to the stanchions. (Works at least great for Betor forks).

[caponerd]

Originally Posted by PSchrauber

FWIN / FYI theses low temp. solders need a rough surface to cling to the applied material, like Lumiweld for example. How will you get the places on the stanchions rough that have to be repaired without doing more damage as you already have?

Befor you get the experience about the meaning: a poor man pays twice, why not ask a hard chrome company if they could give your stanchions a new coat of chrome?

I know there is the route to Canossa but there is always the route back too!

I had the same issue and mine where bend too! Now they are straight, and shiny everywhere. Another good reason to do so is wear at the lower fork tubes that work as guide bushing for the stanchions. You can compensate the wear inside the lower fork tubes by adding some chrome material to the stanchions. (Works at least great for Betor forks).

Short of just buying new stanchions, hard chrome is the best solution.
Regarding bent forks, I learned a long time ago that almost all forks on old motorcycles are bent. Some more, some less, but if you take any high-milage fork tube and check it with a straightedge or on a surface plate, you'll find that it's bent.

[PSchrauber]

Originally Posted by caponerd

Short of just buying new stanchions, hard chrome is the best solution.
Regarding bent forks, I learned a long time ago that almost all forks on old motorcycles are bent. Some more, some less, but if you take any high-milage fork tube and check it with a straightedge or on a surface plate, you'll find that it's bent.

Yep!

To get them straight again they has to be bend back, this cause cracks and additional marks in the chrome plating.
When you want do rechrome your stanchions a straighned up is better done in forehand most companys that offer rechroming can straighten them too, (up to a accuratness of 1:500).

Expecially if you don't get new fork stanchions a good solution, the price is for a 35mm Diameter around 500 - 700mm long stanchion equal to a new one if you can get any, around 100€/piece or 200€/pair (without tax and straightening (which is charged by used time for getting them straight again)).

[kantuckid]

I'll also mention "Steelalloy" a product that has a crappy website but is one of those magic alloys that with low temps you can do repairs.They sell steel epoxy on ebay if you want to search. They also make those magic rods you see at the fair where they are welding aluminum cans etc.. The issue with it is a minimum purchase of $65 for 1#. Maybe I'll start on the state fair circuit at age 68?
Yes I know the adage of paying twice-I did in fact make a living in another life of repairing other peoples stuff. The reality is I love the challenge of making something work again, that's any something!

[spoon]

Another option - after you are sure the tubes are straight- visit an electroplater shop. An accepted repair on aircraft struts (similiar to fork tubes) is to repair nicks ect. with copper by brush plating. If the shop has the equipment the repair can sometimes be done without taking anything apart. The surface is cleaned and preped electroliticly and the copper is put on in the same manner just to the affected area. Some fine sanding may be needed to finish up. All you will see is a copper dot the size of your ding. Check it out.

[RecycledRS]

Now that sounds like a safe, inexpensive and long lasting fix. Will have to check out local area for availability.