Surface Finish Buffed out On Lathe

Hey guys, just tore into my 2004 Honda CRF250R forks and have these wear marks along the shaft.  I saw one video of a guy polishing the stanchion tubes on the lathe with polishing compound.  My tubes dont have any pits or gashes or chips.  They have these discolored streaks along the shaft.  

 

My question is, is it worth the effort to take them into the shop and put them in the lathe and polish these forks up?  I have access to machine lathe sin my shop class.  Should I hit the streaks first along the streaking or should I focus on polishing the tube while spinning so as to keep it round and true? 

 

I also saw him with a green scrubbing pad, I think you can get these in different coarseness?s this recommended?

 

I am thinking about wet sanding at 2000 grit and then dropping down to 1500 if that doesn't work.  This is all while it is spinning at about 500 rpm and my hand holding the paper.

 

I hate to be a trailblazer on my own forks, but I can't find any information of guideance on this.  Of course if it turns out good, I could offe the service to others here for cheap! :ride:

 

I'm going to post some pictures of my forks so here goes:

 

Ok, I'll post them soon....

 

 

 

 

Here is the video I watched:

 

Here are the picturesIMG_20140215_161841_966.jpgIMG_20140215_162006_094.jpgIMG_20140215_162017_549.jpgIMG_20140215_161951_176.jpg of one tube, the other is milder

I will sometimes run a tube on our lathe and use a green scotch brite - but not too often.  I don't think you will find any real gains if you are using a quality seal already.

I will sometimes run a tube on our lathe and use a green scotch brite - but not too often.  I don't think you will find any real gains if you are using a quality seal already.

 

I would venture to say that if the tubes are in good condition then the benefits are probably small.  However as the man in the video says, if the tubes have little nicks/burrs/pits then polishing the tubes removes those sharp edges that can adversely affect seal-life.  Obviously if the tubes are too far gone, then polishing won't help.  I've also read that some suspension tuners polish tubes and impart a cross-hatch finish that helps retain trace amounts of oil for reduced stiction and better seal-life.

 

Without knowing what kind of pad he's using exactly or grade I can speculate that the actual polishing comes from the jewelers rouge or diamond polish he uses on the pad.  When I had my forks apart I hit them with 3M scotch-brite pads (first red 7447 and then gray 7448, saturated in WD-40).  It cleaned up the majority of the discolorations on the tubes.

 

If your fingernail doesn't catch on those marks then I wouldn't worry about it… polish it lightly and forget about it.

Some shops put a cross hatch on the tubes, I did that to my wp forks and it did reduce stiction "some"

Thanks for the help guys, I'm gonna see what I can do on the lathe then, but I won't put too much effort into this method.  They don't leak real bad, it's just enough to notice.

When you polish the tubes on a lathe - no matter what medium you use for the polishing - you will end up with a crosshatch anyway.

Sure, if you use the finest polish paste you wont but if you use scotch pads or grit paper, you will.

 

IMO its very important to do it.

When you polish the tubes on a lathe - no matter what medium you use for the polishing - you will end up with a crosshatch anyway.

Sure, if you use the finest polish paste you wont but if you use scotch pads or grit paper, you will.

IMO its very important to do it.

What's your personal process?

Depends on the kind of wear the chromtubes have.

Some have quite noticeable wear lines over 2/3 of the stroke. Especially when the bike was ridden in mud.

 

In that case I start with 800 grit (EU grit, it's differnet to US grit!!!) and finish off with 2000.

If you want to, you can finish it up with a fine polish paste.

 

Depends on how much effort you want to put into it because it will wear again after around 10-20 hours with the OEM chrome, haha!

Edited by Vietze

and what do you do if there in visually good conditioin?

nothing or do you still polish with 2000?

I think it's a good idea if you can just to ensure you remove any high spots from nicks , watch out for the brake side ! That could hurt

and what do you do if there in visually good conditioin?

nothing or do you still polish with 2000?

 I still polish them with 2000 to apply a crosshatch but you will find various opinions on that.

Edited by Vietze

and what do you do if there in visually good conditioin?

nothing or do you still polish with 2000?

same here as Vietze.

On every service the tubes and the piston rod (shock) where polished in a 3-step process.

and i think as well, it's a good thing to do.

i also polish as vietze and finish with 1500

I think it's a good idea if you can just to ensure you remove any high spots from nicks , watch out for the brake side ! That could hurt

 

 

 I still polish them with 2000 to apply a crosshatch but you will find various opinions on that.

 

 

same here as Vietze.

On every service the tubes and the piston rod (shock) where polished in a 3-step process.

and i think as well, it's a good thing to do.

 

 

i also polish as vietze and finish with 1500

 

Do you guys polish also anodised tubes like the black KYB from Kawi lets say!

 

i serviced one the other day! it did look too bad so i thought off leaving it since it could wear off the COOL factor...hhmmm

That's dlc

i found dlc polished with 2000 but i never do that

You definitely have to be carefull with coatings.

Especially the crappy OEM Kawa coatings...

 

However, all coatings can and sometimes have to be polished in order to gain the maximum performance.

 

I think 2000 grit wont grind the coating off but I would rather use a fine scotc bride or polish paste for coated legs.

 

At least that is what I do when I get coated chromelegs back from my coating guys.

You definitely have to be carefull with coatings.

Especially the crappy OEM Kawa coatings...

 

However, all coatings can and sometimes have to be polished in order to gain the maximum performance.

 

I think 2000 grit wont grind the coating off but I would rather use a fine scotc bride or polish paste for coated legs.

 

At least that is what I do when I get coated chromelegs back from my coating guys.

never used polishing paste, does it leave a crosshatch or if you have one does it take it away?

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