Thread: 2nd hand Jet machines - surface rust and disassembly.

Originally Posted by MSFletcher

I have recently purchased a Jet JJ-8CS jointer and a JPM-13CS thicknesser. Both were stored in a garage prior, and both have some surface rust to most exposed metal surfaces that I need to remove.

My question is, how far can these machines be safely disassembled to aid in the removal of the rust? The manuals show exploded parts views, but I'm wary of undoing a bolt and finding later that I have thrown the whole machine out of whack.

Alternatively, can anyone recommend someone in the Sydney area who can competently undertake this sort of work?

jet-708458k-model-jj-8cs-8-quot-closed-stand-jointer-38.jpgStarting with the Jointer first .....

I assume that these photographs match the models of machinery that you are referring to.

You should be able to remove any corrosion on the cast iron in-feed and out-feed table, and on the fence, without disassembly - although the fence come on and off easily. I use 600 wet & dry paper (the black stuff - I think it's called carborundum paper - not sure). I use the wet & dry paper on a sanding block, and lubricated with Kero or WD-40. The bulk of the corrosion will come off easily in the first few minutes. Make sure you wipe all of the sanding residue away afterwards, then protect immediately with something like CRC-336. The 600 wet and dry will not remove any serious pitted corrosion. If you want the cast iron surfaces to look shiny like they did when they first came out of the factory, you'll have to keep going with the lubricated wet & dry, working up through the grades of paper until you're satisfied. I only ever use 600 wet & dry, and don't bother going any higher in the grits.

If there's corrosion on the drum, you should be able to remove the cutter blades, and clean the rust off the drum without removing the drum from the machine. Give it a new set of cutter blades while you've got it apart. While you've got the drive belt off the cutter head, spin the cutter head by hand. The bearings should run smoothly. If you can feel any slight roughness in the cutterhead bearings, it'd be a good idea to replace the bearings. You'll need a bearing puller to get the old bearings off, and you may need access to a press to put the new bearings on the cutterhead shaft. You should be able to get replacement bearings from just about any good Bearing Shop.

Pop the back cover/s of the machine and make sure that the cabinet is clean of sawdust, and give it a new drive belt while you're in there. Clean and lubricate where it looks appropriate. Lithium grease seems to work well for me, but some people swear by drylube type lubricants for lubricating slow moving surfaces because the drylube doesn't collect as much saw dust. Other people use the pressure pack motorcycle chain lube, as it supposedly doesn't attract dust once the solvent has evaporated (a minute or so after spraying).

If the Parallelogram mechanisms for the in-feed and out-feed tables are corroded and/or stiff to move, then you're in for some detailed and fiddly work. Disassembly of the parallelogram movements on most jointers is relatively easy with normal tools, but re-assembly can be a pain. You usually have to shim the dovetail ways on the parallelogram movements to get rid of the slack, and the mechanism to get the two tables and the cutter head co-planar can be very fiddly. Then you'll need to adjust the out-feed table relative to the cutter head to eliminate snipe. If you can avoid disassembling the parallelogram movements, you'll save yourself a lot of fiddly and time consuming work.

jet-708524-main-lg.jpg Now, as far as the Thicknesser goes .....

Again, you should be able to remove the corrosion from the table without any disassembly, same wet & dry process as above.

Remove the access panels from around the cutter head and table, and from the lower back of the machine. You should then be able to remove saw dust, remove corrosion, and relubricate the height adjustment mechanism and the feed roller and feed roller drive mechanism without further disassembly. I'd replace the drive belts while you've got it apart. If the cutterhead is corroded, proceed same as above. Check the bearings on the cutter head and proceed as above. Check the feed rollers. If it's got rubber feed rollers, replace any that have perished rubber. Make sure that the anti-kick-back pawls move freely through their full range. Lubricate were appropriate. Note, if the anti-kickback pawls are nylon, you usually do not lubricate them --- although some manufacturers suggest lubricating the nylon anti-kickback pawls with graphite - check your manual. Turn the feed rollers by hand and make sure that there's no frozen bearings etc. Put it back together. Run some stock through to test the machine. If you get snipe at the beginning or end of a board, then adjustment of the table, and/or adjustment of the cutterhead and/or feed rollers is required - check your manual for the specific way to do that adjustment. Provided no one had fiddled with those adjustments in the past, they are probably still set at factory settings, so just avoid moving any bolt or grub screw that looks like an adjustment.

In general, you should be able to get the machinery in good working condition with minimal disassembly. When I first got back into woodworking, I bought and reconditioned six woodworking machines. Most of the machines that I bought were from deceased estates, or had in some other way been neglected for a few years and were in rusty condition, but with nothing missing or broken. After reconditioning those machines, I sold them on at a profit to help fund my woodworking hobby.

As long as you can avoid disassembling the parallelogram movements on the Jointer, and provided you don't have to replace the cutter head bearings, I'd reckon that you should be able to get that looking reasonable and working well after about four hours work. The Thicknesser will probably take you about 8 hours work, again provided you don't have to replace cutter head bearings, or feed rollers or feed roller bearings.

I hope that info helps.

Regards,

RoyG

Originally Posted by RoyG

I assume that these photographs match the models of machinery that you are referring to.

Roy, thanks so much for your prompt and comprehensive reply.

The machines in the pictures are indeed the ones I've bought (though the jointer for some reason is equipped with a 3 phase motor rather than 1 phase one specified in the manual and on the plate attached to the outside of the base).

The rust seems to be light surface rust, but it's present on lots of relatively hard to get to surfaces like the height adjustment columns in the thicknesser. I'm heartened by your time estimates, though I suspect I'll be adding a zero to each of them.