The Old Lawnmower Club
Collection, Preservation and Display of Old Lawn Mowers
X

Back honing

Enter a word or two to search the forum section and click the Search Forum button.
robint Sun, 12/08/2018

I am constructing a system with motor and reduction pulleys to allow back honing in situ.  Can anyone advise

a) what speed show I use for a typical cylinder rpm

b) how long is a typical back hone session, 5mins 10mins, half hour?

c) what grade of grit/oil to use

This assumes that the bottom blade and cylinder are serviceable

Will post pix of my rig

Cheers

Robin

PS why doesnt forward honing work? surely the blade tends to be self sharpening?

 

Forums

Chris G Sun, 12/08/2018

I do appreciate the endeavour but given it is possible to get a cylinder and bottom blade properly sharpened & painted for circa £30 it put me off for sure.

As for the questions, I guess it would depend on the condition of the work to service and the experience of the machinist.

Hope others will chime in and very interested in what you come up with on this.

wristpin Mon, 13/08/2018

More usually referred to as back lapping. Definitely falls into the category of A Frequently Asked Question on this forum - should be a Sticky!

Is not a substitute for a properly ground cylinder and bottom blade.

Is a maintenance procedure for cylinders that have been relief ground and are in good condition.

Is performed with a specific water based lapping past, not an oil based valve lapping paste.

Is usually a waste of time unless the above criteria are met.   

robint Mon, 13/08/2018

£30 !! not where I am, I have been quoted £50, and I have to bring the mower in as it is lapped in situ

As I have the motor and pulleys sitting around I thought I would give it a try