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Collection, Preservation and Display of Old Lawn Mowers

Ransomes Certes Mk12 overhaul.

I'm having difficulty finding info on the Certes (hand mower) series so I thought I would post some of my photographs during the refreshment of this very late looking Mk12.

I know it's a Mk12 because the handles don't have the third dimension bend; the cross-point is bolted, and most of the mower has UNF fixings.

The name plate is missing from the gear cover.

I haven't found yet which parts are to be what colour, and it has been repainted in the past, so I'm mostly copying what I find, except that I'm not using a grey hammer finish paint on the alloy castings.  Were these painted at the factory?

I'm using Ransomes Green for the green parts (!) and Hammerite smooth silver for the castings and rollers.  The silver is brushed on except for the outer faces which are sprayed from a can.


Photos are at…


I found the roller bearings dry and worn but the cutter bearings were good.

David Bouchard Tue, 11/11/2014

I've put in a bit of effort now, and received a lot of advice from Dave Bolland thanks very much.

This machine is generally quite worn - no one part is particularly bad but it has generally seen a lot of use.

I am doing a sympathetic overhaul, so only a couple of new bearings.  I don't think there's any point in putting precious new old stock parts on it as it is perfectly serviceable.

I've painted the side frames, both rollers and some of the fittings.  I sprayed the roller green from a can on Saturday and that was very successful - a dusting coat first to key the new paint, than just one further coat and it looks great.

The grassbox and cylinder have gone for shot blasting and then I'll paint the cylinder and fit it.

The grassbox still has small dents.  I took out the worst of them this morning and I'll improve it one the blasting and undercoating are done.  Then I'll make good the undercoat and spray it in Ransomes Green.  The inside will be red oxide as before.

Now to look for the proper decal - 4.1/2" x 3.1/2" grey and red rectangular , very modern looking.  I've never seen the CERTES decal - I wonder if I have to use Lettraset?   Does that still exist?  The CERTES letters are about 1/2" tall.

Edda Wed, 17/02/2016

Hi David,

I have just acquired a certes 14inch MK 6. I have a couple of questions the grease nipples look a bit worn do you know what size they are 5/16-3BA? Also do you know if the front roller has bearings or bushes, I suspect bushes.