Do I dare take a sander to a jointer infeed & outfeed table?

[Dan Friedrichs]

I think I was one of the ones who jumped to the incorrect conclusion - forgive me; but sanding cast iron unnecessarily (or incorrectly) could be a quick way to completely ruin an expensive jointer.

That said, if you are 100% sure that both ends rise slightly up (despite it being somewhat unlikely that both would do it the same direction and in exactly the same amount), as long as you don't sand near the cutterhead at all, the worst thing you could do is sand too much off, but that shouldn't hurt your jointing operation.

I'll say again, though, that 0.005" is WELL-WITHIN accepted specs. If you bought a brand-new one and had this problem, NO manufacturer would offer you any remedy. You should not be seeing a problem in jointed boards that can't be fixed with a bit of clamping pressure with that small of an error.

If the error really bothers you, though, I'd first try to adjust the beds such that the ends get lowered 0.005" (even if that means the tables will now be non-coplaner), and see what that does to the error.

["Patrick G Rainsberger"]

One last reply. I'm not going to use my RO sander. You have all talked me out of using it, but I am thinking of using 3M Stickit paper on my Granite Surface Plate that I picked up at Woodcraft. The plate is about 15 lbs. It came with a report card that rated it flatness at .001 mm. It measures 9" X 12" X 2". If I can't get 3M Stickit paper that size I'll have to glue a sheet of sandpaper to it. If I keep the sanding to the outside edge of the tables only, I don't think I'll ruin my jointer.
http://www.woodcraft.com/Product/200...ace-Plate.aspx

again--thanks

[Norman Hitt]

Patrick, I kinda have doubts about how much control you will have using that surface plate, and I have a suggestion you "Might" want to consider. To simulate what I did on my old jointer, AND to control where you are cutting so as to cut down ONLY the high area without dipping off toward the end or sanding any of the flat area, I suggest the following, (which is similar to what JR suggested).

Go to the Borg and purchase about 30" of the 1" or 1 1/2" steel square tubing, and get a small roll of "GOOD quality" 80 and 120 grit Emery cloth, (or sheets you can cut into strips if you can't get a roll.
Cut a strip about 18 or 20" long and glue it to one side of the square tubing, (starting at one end.

Next, cut about a 4" long strip and glue it on the same side of the tubing to the other end, BUT glue it with the abrasive against the tubing. This will give you a cutting surface to work on the high end AND a straight line contact point on the other end that will also keep the tubing from scratching the jointer bed in the flat area.

Next: Use a black magic marker or sharpie and draw a line across the jointer bed at the end of the dead flat area. Now the work starts,

Make all your strokes back and forth in line with the length of the jointer bed, keeping the downward pressure evenly spread over the length of the square tubing. Check your progress occassionally with your straight edge so you can make any corrections if needed.

When you see scratch marks getting close to the line you drew across the Jointer bed, you are getting close to flat and need to closely monitor your progress by dragging your straight edge across and looking for light under it (gap) and change to a finer grit to finish, see below).

I would put the 120 (or whatever finer grit you get on another side of the tubing, (In the same manner, including the piece at the other end), and continue with this grit until it is flat, and it should be reasonably polished with this grit.

Anyhow, this is just a suggestion of how I would do it to assure no dips due to lack of control of the grinding media, and as I said before, it did work for me, but good luck with whatever method you decide on.

Let us know how it all works out.

Ps: I suggest using the Emery cloth because I was always taught (and believe) Sandpaper is for wood, but Emery cloth is for metal. I do know it holds up better.

[Chuck Wintle]

Has anybody ever taken a RO sander to the bed of a jointer to knock down the high spots?
I have an 8” 74” jointer that is perfectly flat in the center 54”. The last 10” of the infeed and outfeed table rise .005 to .006”. When I edge joint two board 27” long they are perfectly straight when put together. When I edge joint two board 36” or longer and put them together they touch in the center but don’t on the ends. I can slip a .007 feeler gauge between The two 36” boards on the end. I’m using a veritas 36” steel straightedge and a oneway multi gauge as measuring devices.
I started a thread last week ‘Grizzley Jointer Fence II’ The thread ended before I had figured out what was happening with the longer boards. The end of the board is being held above the flat part of the infeed table while the other end of the board is going through the cutter. When the board comes off the high end of the infeed table the end of the board that just went through the cutter is now raised off the table. When the board is going off the end of the outfeed table, the cutter is cutting deeper into that end of the board. I can put two boards through the cutter 25 times each and I never can get them to touch on both ends.
Would you start with 320 grit? Any ideas?
The Jointer is out of warrantee.

Patrick,
Good luck with the jointer tables...just a question but have you let anyone else measure to confirm your findings? not saying your measurements are incorrect but an independent look might reveal a different situation.

[Frank Drew]

For what it's worth, the results that Patrick says he's getting when jointing longish boards (too much taken off the ends) are just what you'd expect with the tables "sloped" up at their far ends, as he describes.

["Patrick G Rainsberger"]

Patrick, I kinda have doubts about how much control you will have using that surface plate, and I have a suggestion you "Might" want to consider. To simulate what I did on my old jointer, AND to control where you are cutting so as to cut down ONLY the high area without dipping off toward the end or sanding any of the flat area, I suggest the following, (which is similar to what JR suggested).

Go to the Borg and purchase about 30" of the 1" or 1 1/2" steel square tubing, and get a small roll of "GOOD quality" 80 and 120 grit Emery cloth, (or sheets you can cut into strips if you can't get a roll.
Cut a strip about 18 or 20" long and glue it to one side of the square tubing, (starting at one end.

Next, cut about a 4" long strip and glue it on the same side of the tubing to the other end, BUT glue it with the abrasive against the tubing. This will give you a cutting surface to work on the high end AND a straight line contact point on the other end that will also keep the tubing from scratching the jointer bed in the flat area.

Next: Use a black magic marker or sharpie and draw a line across the jointer bed at the end of the dead flat area. Now the work starts,

Make all your strokes back and forth in line with the length of the jointer bed, keeping the downward pressure evenly spread over the length of the square tubing. Check your progress occassionally with your straight edge so you can make any corrections if needed.

When you see scratch marks getting close to the line you drew across the Jointer bed, you are getting close to flat and need to closely monitor your progress by dragging your straight edge across and looking for light under it (gap) and change to a finer grit to finish, see below).

I would put the 120 (or whatever finer grit you get on another side of the tubing, (In the same manner, including the piece at the other end), and continue with this grit until it is flat, and it should be reasonably polished with this grit.

Anyhow, this is just a suggestion of how I would do it to assure no dips due to lack of control of the grinding media, and as I said before, it did work for me, but good luck with whatever method you decide on.

Let us know how it all works out.

Ps: I suggest using the Emery cloth because I was always taught (and believe) Sandpaper is for wood, but Emery cloth is for metal. I do know it holds up better.

Norman,

Thanks for the details. After I posted my 'One last reply' I realized that the surface plate might give me a super flat surface, but I wouldn't have control with such a large plate. I then thought of my Norton water stones, they go from 220 to 8000, but I like your idea much better and will post my results when I'm done.

[David Giles]

Be sure to thoroughly wet the surface first to raise the grain before sanding.

Sorry, couldn't resist.

[Andrew Pitonyak]

Be sure to thoroughly wet the surface first to raise the grain before sanding.

Won't be required if he uses cast-iron-sanding-sealer, either that or use a hand plane to shave it down... :-)

[Ruhi Arslan]

Won't be required if he uses cast-iron-sanding-sealer, either that or use a hand plane to shave it down... :-)

I would make sure sure to use planes purchased from HF not from LV, they all come from the same factories anyway...

[Chris Rosenberger]

Chris,

Did you have the same problem when jointing as I before you sanded the table. What was your procedure? I'm still waiting for Larry to respond but I'm interested in what you said you did to solve this problem

My problem was the same as yours. The ends of the tables were high. I used a Festool RO 150 sander with a hard pad. I started with 150 grit discs & worked up to micron discs. I kept the sander moving & checked it with a straight edge often. I thought it worked but since the experts here said it could not be done, maybe I dreamed it.

["Patrick G Rainsberger"]

I started this post back in 2011. I became quite frustrated with the answers I was getting. I pretty much disappeared from Sawmill Creek. There were too many people chiming in that didn't contribute anything to the conversation. I view this website as a conversation, not a lecture room. I feel I need to tell you what I did to solve this problem.
I started off using the RO sander with 100 grit. It didn't touch the problem. I went down to a 60 grit and it still didn't do anything. I ended up using a belt sander with 60 grit sandpaper. I must have used 20 belts to finally get the surface flat. It took me at least 2 days to accomplish this. I put a few dents in the surface when the belt sander slipped, but they don't affect anything. The surface has been flat and I've had no problems.

[Doug Herzberg]

I started this post back in 2011. I became quite frustrated with the answers I was getting. I pretty much disappeared from Sawmill Creek. There were too many people chiming in that didn't contribute anything to the conversation. I view this website as a conversation, not a lecture room. I feel I need to tell you what I did to solve this problem.
I started off using the RO sander with 100 grit. It didn't touch the problem. I went down to a 60 grit and it still didn't do anything. I ended up using a belt sander with 60 grit sandpaper. I must have used 20 belts to finally get the surface flat. It took me at least 2 days to accomplish this. I put a few dents in the surface when the belt sander slipped, but they don't affect anything. The surface has been flat and I've had no problems.

Patrick, I saw your post for the first time today. I'm glad you came back to give the rest of the story. I'm restoring an old jointer and am more interested in getting the surface rust off than anything else at this point, but I have thought about how I'm going to get the tables flat if I need to and the information in your thread was helpful.

[Steve Wilde]

Old thread but this is probably as good as any place to ask. I have a DJ20 that I need to adjust the beds to coplanar. I have the instructions on how to do it, but I can't find a spanner wrench anywhere to adjust them. Anyone know of a good source? I checked online a bit and thy were all $35+. I was really hoping for a cheap wrench since I hopefully won't ever be doing it again once it's set.... Thanks

[Al Launier]

This also is the first time I've seen this thread. When I read the OP's initial post what immediately came to mind was that the infeed & outfeed tables were perhaps out of alignment. Reading further I noted that others thought he same, plus there were a number of other proposed solutions.

I can certainly say I had my problems when I purchased my jointer as I couldn't get the jointer to mill a flat surface that was parallel to the top surface. Now before anyone jumps the gun and states that a jointer is not supposed to mill parallel surfaces I must say I already know that. In my case I tried jointing boards that had been run through the planer and the result was boards coming off the jointer that were like clapboards, tapered from one side to the other. I thought I was using the wrong technique, even after Glenn Bradley took pity on me and sent me a homemade video of him showing me the correct procedure for feed a board through a jointer. Still didn't work. I even had a local woodworking friend who was very knowledgeable and very experienced try my jointer to no avail. What to do?

I subsequently ran across a recommendation for a comprehensive book entitled "CARE and REPAIR of SHOP MACHINES", A Complete Guide to Setup, Troubleshooting, and Maintenance authored by JOHN WHITE. Let me say this is an extremely detailed and well written book with clearly stated procedures for maintaining shop machine tools. I followed the procedure detailed by John White and damn if that didn't completely take care of the jointer problem. The tables were not co-planar and required shimming to correct – a relatively easy fix. I can now enjoy jointing wood with complete confidence.

So, I would strongly recommend that anyone involved with equipment used in woodworking consider buying this book. It is everything it claims to be. It sells for only $19.95 and is a wealth of information for Table Saws, Jointers, Thickness Planers, Drill Presses, Router Tables, Miter Saws, and maintenance of other equipment. Please know that I have no affiliations with this author, or anyone connected to him or his retail sales other than being a one-time purchaser of this large book with many illustrated photos. This would make a wonderful Christmas Present.

[Bob Grier]

Steve, I had the same problem. I gave up after a couple hours looking for the wrench and tried gripping the little bit of round stud sticking out. I didn't want to do this because of potential scuffing of the stud but it turned out that the studs turned very easily (after set screws were backed off) and I was able to adjust the beds with no problem. You might try something like this, maybe even use a piece of rubber between the jaws to avoid scratching the adjusting studs/rods. If they don't turn easily, then nothing lost.