Cutting consistent shims 1/32 to 3/32 thick

[Aaron Connor]

I need to cut some long shims for a construction project, between 1/32 and 3/32 thick. At 1/8+", I can use the portable planer - so no issues there.

Accuracy is quite key, as this is shimming for flooring. I am concerned that working at 1/32 increments on longer pieces, I may not get the needed consistency with a contractor table saw. Other than gluing down an 1/8" shim in it's final place (it will be glued) and running a power planer over it, does anyone have any recommendations?

Thanks!

[Ole Anderson]

This gadget for your TS from Rockler works well for me:https://www.rockler.com/thin-rip-tablesaw-jig https://wac.edgecastcdn.net/001A39/prod/media/6f2iIJdfiy1XrhEsite/6771CE870744C1532C2190A4A163EC62.app1_157547039839 8-1_L1800.jpeg
or this one: https://www.rockler.com/magswitch-ultimate-thin-stock-jig-rip-guide-attachment

[Brian Tymchak]

Assuming these shims are not tapered, I would use a thin-rip jig or technique on a table saw. I use a contractor style saw in my shop every day with no concerns regarding accuracy. I've cut strips as thin as .075". I would put a sacrificial board on your fence, use a rip blade, and a splitter behind the blade. Start with a wider piece of stock as long as you need and push on the outside portion thru the cut. It might help a bit to wax the sacrificial fence. You can knock out a bunch of strips in pretty short order that way.

[Maurice Mcmurry]

For non tapered I use a vacuum thing that I used to call a shooting board.


https://youtu.be/hLsU21ZHueY

[Zachary Hoyt]

I would use a bandsaw if you have one that will cut straight with a rip fence. The shims need to be consistent, not really smooth, if I understand the application correctly. A table saw would work too but it's harder (at least for me) to cut really thin strips like that on the table saw. A drum sander is also nice for this, if you know someone who has one. That would be the way to get smooth shims if they're needed.

[Kevin Jenness]

Plastic laminate and veneer are available in variable thicknesses.

[Tom M King]

However you run them, once you have a setup for a given thickness, cut a bunch of them out of scrap. Some years ago we finished the inside of a large room with windows all around that was built by a friend of mine that wasn't a builder. I think we made 20 different thicknesses of shims for the window jamb extensions.

I still have the extras in a large Sterilite plastic bin filled with smaller boxes, and they have come in handy multiple times since we ran them. The time making them was nothing compared to the time they saved then, and since.

[John K Jordan]

FWIW I’ve made thin pieces at precise thickness by resawing wide strips on the bandsaw (making them a little thicker than needed), sand to final thickness on the drum sander, then bandsaw rip to desired width. Doesn’t take long.

Not having both of these tools might require a visit to a friend’s shop. If you add your location to your profile maybe someone in your area will offer to help.


I need to cut some long shims for a construction project, between 1/32 and 3/32 thick. At 1/8+", I can use the portable planer - so no issues there.

Accuracy is quite key, as this is shimming for flooring. I am concerned that working at 1/32 increments on longer pieces, I may not get the needed consistency with a contractor table saw. Other than gluing down an 1/8" shim in it's final place (it will be glued) and running a power planer over it, does anyone have any recommendations?

Thanks!

[Rich Engelhardt]

Plastic laminate and veneer are available in variable thicknesses.<<---This.

[Jamie Buxton]

Drywall shims. These are non-corrugated cardboard strips 3 ft long, 2" wide, and a little less than 1/16" thick. You can buy a lifetime supply for ten bucks or so.

[Edwin Santos]

I like the plastic laminate idea. It will probably be around .040 which is a bit more than 1/32". A double thickness would probably be very close to 3/32".

For really thin shims, it's helpful to know that a standard business card is about .014-.016 so 1/64".
Therefore a double thickness of business card stock will get you to 1/32". I keep a ream of card stock in the shop for this reason.

[Aaron Connor]

Thanks, everyone! Many great ideas, here - I knew you all would have them!

Don't have a band saw, but do have a drum sander and had not thought of that. Table saw jigs and approaches look good. Prefer to have a glued wood shim, so that the subfloor adhesive is bonding to something structural, else drywall and plastic shims would definitely be the way to go.

Because the joists have sagged over time, and I can't use a wedge. I will probably adjust shim heights in 1/32nd to 1/16" intervals and then either take off half the difference for the end of the glued shim with a power planer or even a sander. If anyone else has ideas on that aspect, feel free to shout out. Thanks!!

[Aaron Connor]

This gadget for your TS from Rockler works well for me:https://www.rockler.com/thin-rip-tablesaw-jig https://wac.edgecastcdn.net/001A39/prod/media/6f2iIJdfiy1XrhEsite/6771CE870744C1532C2190A4A163EC62.app1_157547039839 8-1_L1800.jpeg
or this one: https://www.rockler.com/magswitch-ultimate-thin-stock-jig-rip-guide-attachment

Unfortunately, it sounds like the jig you have doesn't get below around 3/8" on many of the dewalt saws that have the groove about 6" off the blade. Is this the case with yours?

[Earl McLain]

Any reason why leveling compound (might not be the correct name) wouldn't work? It's made for that purpose, but i don't know what the max depth might be. The guy that did our vinyl & tile floors in our 100 year old house 20 years ago used it--no problems yet.
earl

[Robert L Stewart]

Maurice, great jig idea!

Thanks for posting

[Aaron Connor]

I like the plastic laminate idea. It will probably be around .040 which is a bit more than 1/32". A double thickness would probably be very close to 3/32".

For really thin shims, it's helpful to know that a standard business card is about .014-.016 so 1/64".
Therefore a double thickness of business card stock will get you to 1/32". I keep a ream of card stock in the shop for this reason.

Thanks - that is super handy to know... in this case, I need it to be structural, since it will have subfloor adhesive bonding to it.

[Aaron Connor]

Any reason why leveling compound (might not be the correct name) wouldn't work? It's made for that purpose, but i don't know what the max depth might be. The guy that did our vinyl & tile floors in our 100 year old house 20 years ago used it--no problems yet.
earl

That can work for some situations, but not mine.

1 - expensive. 2 - incredibly heavy when the floors are out up to 7/8" and over an engineered beam 3. leveler also has its limitations 4. hard to pour leveler without subfloor (original subfloor was only 1/2" and had slots for forms and was weak) 5 - most levelers don't allow nailing through and have to be repoured if there is an issue and glued flooring is removed. Flooring guys do it as a patch up, but not a fix of the issue... just the tool they have in their toolbelt

[Kevin Jenness]

Can you describe exactly what you are doing or post a photo? Are you shimming over hollow spots in a subfloor that should have been thicker? Have you removed the subfloor already and are shimming the beam surfaces? 7/8" sounds crazy. Should you be replacing the subfloor or joists? Would you be better off sawing long tapered shims? How large an area are you dealing with?

[Aaron Connor]

Can you describe exactly what you are doing or post a photo? Are you shimming over hollow spots in a subfloor that should have been thicker? Have you removed the subfloor already and are shimming the beam surfaces? 7/8" sounds crazy. Should you be replacing the subfloor or joists? Would you be better off sawing long tapered shims? How large an area are you dealing with?

Thanks for the interest in helping. We are shimming on top of joists that were sistered prior to the subfloor being removed - this work was unexpected. Yes, there is a lot of rise and fall in the 60 year old joists, especially where one sits on a stud wall. Joists are have a lot of mechanical/plumbing running through them... and most are LVL sistered... won't be redoing that. One one side of the beam, we could have done tapered shims, on the LVL's, but they are not quite full length, and that really messed up sheet lengths, since they were not all sistered on the same side. The original joists had sagged, so that makes it a little more complicated, but I'm not overly concerned. On the other side, the LVL stiffener is only a 5.5" member set at the bottom of the 2x8s, so shimming on that isn't a good plan.

[Kevin Jenness]

Sounds like your basic nightmare. It seems your shims will have to be closely spaced and carefully stacked to arrive at a level or fair surface. I might be sawing and fastening tapered shims atop the joists or running new sisters, but you are in a better position to judge the best solution. Good luck!

[Aaron Connor]

Thanks - basically, yes. You are right that leveling and tapering shims to the top may be a good option to consider if direct shimming turns into a cluster. I had also thought of screwing a temporary sister on one side, scribing a line and cutting with a band saw, though don't have one.

I am a little leary of removing much material, however - due to joist strength, though there is one that sits very high and that one will come down. Over the length of a joist, they're more like 1/4 out, just across the room there is more elevation... I won't be stacking, just using different lengths of different thickness shims, wood glued to the original joist, and if needed smoothing the top over. That doesn't have to be perfect, as the subfloor adhesive can bridge up to 1/8" gap, so if I'm 1/32 of - no big deal.

To complicate things, the framing crew laid new subfloor out of level in an adjoining room, which is 7/8" out, as well. Happy we have this technology called laser level :)

[Warren Lake]

cut lots of shims on the table saw, long fence not pulled back as I didnt have a pull back fence and no false fence attached as it was not as much of a thing back then. You grow up one way and sometimes stay that way at least I did depending what was being done, the rips anyway long fence. No guard no splitter no riving knife. Riving knife would be fine if so.

Figure it out as I go depending on what it is. One way was to put the board in a foot or more then pull it out, flip it over do the rip from the other end till i hit what i had ripped in already then lift it and the cutoff same time. Start again same next one. Its just one example of why no guard for me, the work had to get done and did. Now on one new saw there can be a riving knife as long as no complications its a positive thing.

Not your nanny state technique but worked fine, never an issue. You dont say how long your pieces need to be.

[Tom M King]

Can you sister on the other side of the joists, and set them to lines? I'd do that before doing a lot of shimming.

Here is a picture of a small hip roof that we sistered to make the roof planes flat. It was such a low pitch that any sag would make a spot to hold water. I put a standing seam roof on it with heavy gauge metal, and it sheds water in spite of the almost flat pitch. Sisters were straightened on a jointer.

I set the outer ones to a line, and used different length levels, up to a 78" to set the others by, to make sure it was a flat plane. It had also been built with no ventilation. I extended the overhang a little to add soffit vents all around.

[Maurice Mcmurry]

Maurice, great jig idea!

Thanks for posting

Thanks! It is by no means original to me. Vacuum holding and lifting has lots of uses. I first saw it in a wood shop when Mike Dulak, the mandolin maker, showed me how to use a shop vac to create a hold down for work you just do not want to, or can not hang on to.

[Warren Lake]

its been around in industry for a long time. I still want to add it to the stroke sander. Doing small parts and vibration in the machine and they wander a bit

[Maurice Mcmurry]

its been around in industry for a long time. I still want to add it to the stroke sander. Doing small parts and vibration in the machine and they wander a bit

I am inheriting a stroke sander. I will add a vacuum hold down for sure!

[Kris Cook]

I don't know if this helps but I was trying to figure out how to explain a technique for ripping consistent thin strips safely. This video does a much better job than I could.

https://www.youtube.com/watch?v=0YpuAZOIj88

[Richard Coers]

You can buy commercially made veneer that is 1/16" thick at Certainly Wood. You can also run straight grain stock through a thickness planer on top of a, 8' long piece of particle board to support the material better.

[Ole Anderson]

Unfortunately, it sounds like the jig you have doesn't get below around 3/8" on many of the dewalt saws that have the groove about 6" off the blade. Is this the case with yours? I have a G1023 and the jig cuts as thin as needed. The picture is from the Rockler site, not my saw.