Ajax grass box restoration
I'm trying to revive an Ajax Mk3. With your help, I've got the body of the mower tidied up and repainted but the remaining item is the grass box. It's basically sound; there's no deep corrosion and only a few minor dents - but a fair amount of surface rust/pitting and "dings".
What's the best way to prepare it for repainting? I've asked about sand blasting but the chap said it would be safer with a "finer" process but which could cost sixty quid! I've got a fair amount off with light sandpaper and dry wire wool but, with the profiles and slight dents, it's an awkward surface and it would take months to get it perfectly bare; is there an OLC recommended way of getting it good enough for painting?
Thanks again for the help
Hi Nigel, in my experience whichever method you use to strip the paint will be messy and time consuming.
I have found these nylon wheels quite good and a reasonably fine grit sanding disc, about 180 as any coarser will leave scratches that might show after painting as paint sinks into the substrate.
The inside will be the worse and will probably require patience.
See if you can find someone who does Soda blasting , less aggressive even than worn glass beads. If you have a compressor you can make a Soda blaster to do a one off job using little more than a couple of pieces of plastic tube. Google and YouTube will show how.
This grade of glass is good and not too aggressive or expensive.
For bigger stuff I am going to have a go at soda via pot blasting as my cabinet is too small, it will make a mess either way, need a compressor with more puff as well.
Thank you all for the advice. I think I'll have to go in NM's direction and accept that it's going to be slow and painful work with fine sand/emery papers; which, I'm afraid, will probably involve a compromise on the standard of the end result. I don't have a compressor or - more importantly! - the technical background to know what to do with it! and I've got to keep a cap on the cost of this "project"!!
Back to the shed.
Hi, thought I’d managed to find a short cut to putting pictures up by copying and pasting but it seems I was wrong, surprise surprise. Here is nylon wheel and arbor.
See if you can find someone who does Soda blasting , less aggressive even than worn glass beads
Walnut shell is another less aggressive option and tends not to heat up (and thus not stretch) thin metal.
Personally, for steel I would use traditional paint stripper gel. Just make sure it's completely washed off and neutralised.
Thanks gtc. My problem is not so much the paint - which I'm sure would respond to a paint stripper - but the rust spots and patches. I've gone for something similar to NM's device called a dome mop sander. At 240 grade it shouldn't be too vigorous; in fact, at grade might be a bit feeble. I'll report back!
I for one would be certainly interested how you progress with this. I have two Ransomes Ajax both MK5, and one grass bin is worse than the other and had slight holes in this. My inital thoughts were to strip down wire wool and inspect the damage and perhaps repair with car body filler? I will take some pictures, but as yet i am just polishing the sides of the aluminum and rebuilding the actual mower as yet.
surface rust can be treated with phosphoric acid. its benign (food additive in coke) it passivates the rust into a black sludge. When done wipe off and wash with bicarb and dry off quickly. when dry apply zinc primer asap as the bare metal will start to tarnish within hours from air moisture
word on the board here is that paint strippers are messy and toxic and not very effective as they have been watered down by EU regs
I once had a steel cabinet I wanted to remove paint but the man advised against it because shot blasting will stretch and warp sheet metal
I have ordered an abrasive nylon wheel for my angle grinder 240 grade, will revert.
My thoughts are that if the paint is still properly adhered to the metal then you only need to scrub off the surface gloss so the primer has something to grip. Of course rust patches would have to be feathered and treated as above.
I use paint stripper then submerge box in drum of oxalic acid solution.Then wash off. once dry I wipe on vactan to coat any deep rust.I also use filler and then primer filler.I then sand/flat ready for topcoat,then thin top coat.Once hard I sand flat then topcoat.Enamal paint is prone to over spray so one will find it difficult to spray all sides in one go.A system via masking will have to be used.i do the insides then the bulk then the sides.It all takes longer than the rest of the mower.Thats just my way anyway.
Thanks again for all the help. I got a couple of sanding mops - a "goblet" and a "dome " shape. They're good products ( - and I don't know whether l'm allowed to say this but the supplier, Midlands Tool Supplies, gave very good service) but I don't think they're right for this job. I can deal with the old paint and surface rust on the big open areas with sandpaper and wet&dry; I use 80 grade, but lightly, for the first go and then "worn" 80 or less to finish off to avoid the scoring that you warned about. The problems that I'd hoped the mops would deal with were i) cleaning out any pitting and ii) the contours around the stamped lettering and shapes. The mops aren't bad on the pitting but, I have to say, I can do quite well (?) with gently working the areas with newish 80 grade. But I don't get the result I was hoping for around the lettering (the embossed/indented Ransomes and shapes on the side panels); the letters are very close together and I'm concerned that, even though the mops are flexible and 240 grade, by the time I applied enough pressure to get the mop working at the "base" of the letters, I might risk actually thinning the metal at the "top".
And, since the more technical options of blasting, acid and immersion (thanks, cwj123) are embarrassingly outside my comfort zone!, I'm carrying on with the elbow grease and accepting Robint's warning that it won't be a walk in the park!
(Frankly, I bought this machine to cut the grass! I'll give its restoration my best shot but, so far as the more "cosmetic" aspects are concerned and provided that I don't do anything that a more capable successor can't undo, it'll have to meet me half way!)
Thanks for listening!
one of the solution Iam considering for a rotten bottom on my maquis box is to use a sheet of clear polycarbonate - you know the anti vandal stuff they use on bus shelters, its really tough maybe 1 or 2 mm thick. its quite cheap (ca £10)and easier to handle than galv sheet. Could wrap it round and use pop rivets. I would paint it both sides first. It would be very durable, no dings or rust. The inside I would just flap wheel and coat liberally with brushed bitumen paint - solid stuff
whatever floats your boat