Preparing Chrome Cylinders?

[SteveSr]

Hello,

At least I think that it is chrome. Normally I use red Scotchbrite on Nikasil cylinders which works well to roughen up the bore for new rings. However, red Scotchbrite doesn't touch whatever this cylinder is plated with which makes me think it is hard chrome plated.

Suggestions on how to proceed?

 

[SteveSr]

Bump... Any help?

 

[ballisticdoughnut]

I use 240 grit aluminum oxide flex hones for deglazing cylinders. Works on nikasil and hard chrome.

 

[NSEric]

You could lightly sand it with 180 or 240 grit sand paper.

 

[SteveSr]

You could lightly sand it with 180 or 240 grit sand paper.

I may try this next. I think that I have some cloth backed abrasive tape.

 

[Mad Professor]

Wet sand it with a fine wet/dry paper. You can use a solution of dish detergent for the wet.

 

[Breckinridge Elkins]

Hello,

At least I think that it is chrome. Normally I use red Scotchbrite on Nikasil cylinders which works well to roughen up the bore for new rings. However, red Scotchbrite doesn't touch whatever this cylinder is plated with which makes me think it is hard chrome plated.

Suggestions on how to proceed?

I was under the impression that Nikasil was a lot harder than chrome.

 

[cookies]

Get the dingleberry hone, the hatch pattern is much better compared to hand sanding plus there is a lesser chance of sanding the cylinder out of round or going through the plating

 

[sean donato]

I was under the impression that Nikasil was a lot harder than chrome.

It is, and honing it is pointless. If you have an abrasive that will cut it, you'll cut right through it. It's very thin.

 

[stihltech]

I did not know that rings will seat without a crosshatch of some sort. Can someone prove that to me? Please.

 

[Mad Professor]

Get the dingleberry hone, the hatch pattern is much better compared to hand sanding plus there is a lesser chance of sanding the cylinder out of round or going through the plating

It is, and honing it is pointless. If you have an abrasive that will cut it, you'll cut right through it. It's very thin.

Finger honed 036.

 

[ballisticdoughnut]

This cylinder was honed with a 240 grit aluminum oxide flex hone. Two key points here. You must use the proper size hone, and use lubricant. I do this in a solvent tank with solvent running into the cylinder as I’m running the hone. Three strokes clockwise, three strokes counterclockwise is generally all it takes. Finish looks rough in the pictures but I can assure you it’s very smooth. Almost glass like.

 

[Breckinridge Elkins]

Our new solvent tank is "aqueous" I miss the old oil based one.

 

[SteveSr]

I was under the impression that Nikasil was a lot harder than chrome.

Doesn't appear to be from my current experience. Maroon Scotchbrite won't touch it. Abrasive cloth barely touches it.

 

[SteveSr]

Finish looks rough in the pictures but I can assure you it’s very smooth. Almost glass like.

Viewing angle and lighting angle. At an off angle the cylinder looks almost mirror but straight on through the exhaust port you can see some fine scratches with the light from the bottom of the bore.

 

[Bill G]

Our new solvent tank is "aqueous" I miss the old oil based one.

Funny how some think the aqueous is better. I will tell you if you get the mix wrong it will eat paint and dissolve magnesium.

 

[huskihl]

I did not know that rings will seat without a crosshatch of some sort. Can someone prove that to me? Please.

How many newer stihl cylinders have you been into? They shine like a mirror with no crosshatch.

 

[Mad Professor]

How many newer stihl cylinders have you been into? They shine like a mirror with no crosshatch.

OEM Stihl, no crosshatch.

Crosshatch was for cast iron lined cylinders, those would wear in with the rings.

An aggressive crosshatch on a plated cylinder will wear out the rings

 

[SteveSr]

OEM Stihl, no crosshatch.

Crosshatch was for cast iron lined cylinders, those would wear in with the rings.

An aggressive crosshatch on a plated cylinder will wear out the rings


View attachment 1104467

So what you are saying is to just install new rings and run it?

Cylinder in question does show some faint (factory?) abrasion in areas where the piston didn't travel so it looks like there was a little roughness originally to help seat the rings.

 

[Woody912]

So what you are saying is to just install new rings and run it?

Cylinder in question does show some faint (factory?) abrasion in areas where the piston didn't travel so it looks like there was a little roughness originally to help seat the rings.

What I did about 8 years ago along with a gasket delete. Runs like a top