Using a Router as a Jointer

dusty · Post by **dusty** » Mon Jan 28, 2013 12:06 pm

I have not done this before and when I did just recently tried it I got to wondering why not.

Is there a good reason not to edge joint using a straight bit in an under the table router set up.

I learned on my first attempt that if the fences are not set up properly you get a quick lesson in tapers and snipping at the end of the cut. Once the fences are setup properly, it seems to work great.

I am doing this because I do not want to use my jointer to mill MDF if I can avoid it. I have an upcoming project that will make heavy use of veneered MDF.

pieceseeker · Post by **pieceseeker** » Mon Jan 28, 2013 12:22 pm

dusty wrote:I have not done this before and when I did just recently tried it I got to wondering why not.

Is there a good reason not to edge joint using a straight bit in an under the table router set up.

I learned on my first attempt that if the fences are not set up properly you get a quick lesson in tapers and snipping at the end of the cut. Once the fences are setup properly, it seems to work great.

I am doing this because I do not want to use my jointer to mill MDF if I can avoid it. I have an upcoming project that will make heavy use of veneered MDF.

Sounds like a viable way to edge joint. What is the proper way to set up the fence for that particular operation? I'd like to file the info away for future reference when I finally get a SS.

bobgroh · Post by **bobgroh** » Mon Jan 28, 2013 1:15 pm

pieceseeker wrote:Sounds like a viable way to edge joint. What is the proper way to set up the fence for that particular operation? I'd like to file the info away for future reference when I finally get a SS.

To use the router table for jointing, you just set up the left half of the fence so it is a smidge farther out than the right side. Most tables seem to have the ability to slip a spacer sheet in behind the fence to accomplish this (my Bosch does).

Then you set up the fence so the left side is aligned with the router bit.

Overall seems to work well and, if you don't have a jointer or don't want to mess around with the jointer, can be quite convenient.

curiousgeorge · Post by **curiousgeorge** » Mon Jan 28, 2013 2:09 pm

The router table makes an excellent jointer. Just think of the fence as the bed of your jointer and the straight bit is the jointer blade. The left fence is the output side so it has to be even with the blade/router bit and the right side of the fence is the input side of the jointer so it has to be below (behind) the output side and bit. How far you have the left off-set from the right will determine the depth of cut you will obtain. I have found that a piece of Formica stuck to the left fence makes a good off-set if your fence doesn't have adjustability. Just remember, the left fence has to be the side in line with the router bit. I use a straight bit with a top bearing so it is easy to simply use a ruler/straightedge to align the left fence with the bearing without worrying about catching the edge of the bit and not the flute.

bobgroh · Post by **bobgroh** » Mon Jan 28, 2013 4:01 pm

curiousgeorge wrote:...... I have found that a piece of Formica stuck to the left fence makes a good off-set if your fence doesn't have adjustability. Just remember, the left fence has to be the side in line with the router bit. I use a straight bit with a top bearing so it is easy to simply use a ruler/straightedge to align the left fence with the bearing without worrying about catching the edge of the bit and not the flute.

Love that little trick! Getting the fence set right has always been a bit of twitch - your trick should really help.

Gene Howe · Post by **Gene Howe** » Mon Jan 28, 2013 4:35 pm

Another router jointing trick when two boards need to be joined, is to lay them both on the bench, elevated with pieces of plywood. Draw the two boards together so the gap is a smidge smaller than the straight bit you plan to use (I use a 3/4" bit), clamp them down. Now, using double stick tape attach a straight board on one of the two work pieces to serve as a guide for the router. (measure from the center of the bit to the edge of the router plate).
Any slight deviation is mirrored, so both pieces will fit together nicely.

dusty · Post by **dusty** » Mon Jan 28, 2013 5:00 pm

This is going to be a useful tool; one that I have owned for years but never used. I never thought about using it as a jointer (duh).

My left and right fences are home built. Rather than use something to shim the left fence, I am going to make two new right fences. One will be 1/32" thinner than it is now and the other will be 1/16" thinner. When I want to use the table as a jointer, I'll just mount the appropriate right fence ( I suspect that will be the -1/32" version).

I figure I can plane off the needed amount more easily than I can find two shims that thin (shims that will survive in my shop).

bobgroh · Post by **bobgroh** » Mon Jan 28, 2013 5:26 pm

The shims that came with my Bosch were plastic - 3 different thicknesses. I've made up a couple more using thin plastic I scrounged up around the house. Probably more than I really need!

curiousgeorge · Post by **curiousgeorge** » Mon Jan 28, 2013 5:38 pm

Old credit cards, a playing card, refrigerator magnets, etc. Just about anything like these will make a good shim.

reible · Post by **reible** » Mon Jan 28, 2013 6:32 pm

The router jointer idea works, been there, done that.

My question would be are you sure you need to do that operation. Using plywood, mdf core or what ever should cut up pretty well if you can use the table saw, as in no need to joint.

If you have to first cut up the sheets then I can understand that a circular saw might leave edges that need work but then they need to be fixed before you start doing sizing cuts. The point the edges get damaged is the the first point to attack in the process. Unlikely the router is the solution but rather a tool of last resort. Meaning that the better you start off the better you can end.

Just trying to lend some perspective to the process.

Ed