# Blum Tandem Drawers with 3/4" plywood!



## jlozan2 (Nov 2, 2018)

Hey guys so i'm designing some kitchen cabinets for my little brother. For the drawers he wants the Blum 18 tandem slides. I'v e heard these can be a pain to install since the instructions are trash. We plan to use 3/4" Alder stock or 38/4" Alder plywood.

The instructions say that you can only use up to 5/8" thick stock. I figure I can just cut a 1/4" rabbet 1/2" high down the front and sides to compensate for the extra thickness of the stock we plan to use.

My questions are:

1.) Has anyone successfully used 3/4" stock for these drawer slides?
2.) Can I do half blind dovetails if i go with this method or will the 1/4" rabbet show in the front piece?

Here are a few sketches to show proof of concept.


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## Woodmaster1 (Apr 26, 2011)

Check Sommerfeld tools for wood. They carry the Blum slides for 3/4". They are not that hard to install. I just got done installing 13 drawers using the tandem slides and they are awesome slides. Sommerfeld's also has YouTube videos on building cabinets and installing slides.


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## EarlS (Dec 21, 2011)

As I recall, I used Blum slides when I was building my closet drawers and maybe the Mackintosh vanity. It's been a while so the details are fuzzy, but I recall making a test drawer box and figuring out the Blum instructions. Once I determined the specifics, the rest went really well.

If you are putting a drawer front on the box it will hide the 1/4" rabbet. Otherwise, set up 1/2 blind dovetail so the rabbet is in the pin socket on the side panel. I hope I understood what you were asking.


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## jlozan2 (Nov 2, 2018)

> Check Sommerfeld tools for wood. They carry the Blum slides for 3/4". They are not that hard to install. I just got done installing 13 drawers using the tandem slides and they are awesome slides. Sommerfeld s also has YouTube videos on building cabinets and installing slides.
> 
> - Woodmaster1


Would you mind sending me the link or model number to the slides you used? I want to make sure I use the same ones.


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## RichT (Oct 14, 2016)

I buy my Blum hardware from Woodworker Express. Good prices and customer service.

You want the 563F runners. The 563H is for 1/2 and 5/8 inch drawer sides, the 563F is for 5/8 and 3/4" sides. Instructions are on the Blum site and tell you everything you need to know, most importantly the width of the drawer box given the opening width. Also, you can order a full Blum catalog for free on their site that will include all of the data you need as well for runners and hinges.

Regarding the groove showing on the front, you have your drawing wrong. The tail board is the side of the drawer and the front is the pin board. Nothing will ever show out the front, and given the 1/2" distance between the bottom of the drawer side and the groove that's required for under mount, it won't show anyway. That's assuming you're using 1/4" drawer bottoms. If you do 1/2" bottoms, which are really unnecessary for a 100 lb load drawer runner anyway, they will show unless you do a stopped groove. I've had to do that before when I was matching some existing cabinetry. The stopped groove only had to be done on the drawer front and back though since, again, the groove there was hidden in the pins.

For illustration, take a look at the photo (image 3 of 3) of the pull out shelves I put in this upright pantry project I just posted. In this case, the sides are dovetailed directly into the front, but the same concept applies when you are building a standard drawer box that'll have false front attached. The bottom drawer on the pantry is built that way.

P.S. If you use alder, be sure to read up on blotch control. Alder blotches like crazy. You can see my alder projects on my project page as well. Feel free to ask me any questions.


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## Woodmaster1 (Apr 26, 2011)

563F4570B Is the number used on sommerfeld Tools for wood web site.


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## RichT (Oct 14, 2016)

> 563F4570B Is the number used on sommerfeld Tools for wood web site.
> 
> - Woodmaster1


That's simply the Blum part number. It will be the same for any site selling them. 563F is the series (which I posted above), the full number specifies an 18" slide. However, it would be pretty foolish to purchase them from Sommerfeld since they are $40.90 there versus $22.27 at Woodworker Express. Why pay almost twice as much for the exact same product?

Back to Castor Woodworks, why are you using 18" runners? Standard kitchen lowers are 24" deep (exterior), but that will allow you to use 21" runners (you can't put 24" runners in a 24" cabinet). I don't understand why you would use such short ones. Also, don't forget to buy the left and right side locking device for each set.


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## PPK (Mar 8, 2016)

I don't mean to be a pain, but what's your reason for going with 3/4" drawers? Realize that that reduces the usable inside space in a drawer. It'll look rather odd also. Most drawers are 1/2" to 5/8". I've built some pretty large (36" wide x 22" deep) drawers, all at 1/2" sides, and have never had any issues with the sides being too thin. Drawers are a box, which inherently are quite sturdy, so going up to 3/4" is overkill, in my opinion. Just wanted to throw that out there.

Good choice on the drawer slides, though. Blumotion slides are great.


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## RichT (Oct 14, 2016)

> I don t mean to be a pain, but what s your reason for going with 3/4" drawers? Realize that that reduces the usable inside space in a drawer. It ll look rather odd also.
> 
> - PPK


The cabinets in my kitchen, which were here when I moved in, are semi-custom with 3/4" sides and back. It really doesn't look odd at all. That said, I do agree with you that it's overkill. For a kitchen, 1/2" ply is more than adequate.


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## DS (Oct 10, 2011)

Lots of good advice here. 
There IS a version of Blum Tandem for 3/4" drawers. I usually resort to those only when the specified drawer material dictates 3/4" thickness. (Such as specialty laminates, etc.)

Whenever possible, we use 5/8" drawers. Mostly, due to the fact that the guide cost is highly influenced by economies of scale. We get better pricing on the more common guide sizes. (Commodity pricing)

Clearly, this is a preference issue for the drawer thickness with some minor cost differences in the hardware.

It is also common to hide the drawer bottom groove by setting your pins and tails relative to the dado.


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## jlozan2 (Nov 2, 2018)

> I don t mean to be a pain, but what s your reason for going with 3/4" drawers? Realize that that reduces the usable inside space in a drawer. It ll look rather odd also. Most drawers are 1/2" to 5/8". I ve built some pretty large (36" wide x 22" deep) drawers, all at 1/2" sides, and have never had any issues with the sides being too thin. Drawers are a box, which inherently are quite sturdy, so going up to 3/4" is overkill, in my opinion. Just wanted to throw that out there.
> 
> Good choice on the drawer slides, though. Blumotion slides are great.
> 
> - PPK


I have two reasons for going with 3/4" thickness.

1. I plan on doing half blind doevtails using 3/4 stock (knotty alder). I plan on using stock but might use plywood depending on the price.
2. I don't have a big shop, this is a "small" project. I use Sketchup to create a cutlist and plan to maximize my 3/4" plywood. I would like to waste as little as possible. and i feel like buying 1/2" plywood is just gonna give me more to worry about.

If I had a bandsaw i would just mill some 5/4 Alder to 5/8" and call it a day but i'm trying to plan ahead.

Thank you guys for all the info.


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