Blum Undermount Slides - Advice?

[Doug Hobkirk]

I am about to make two quality drawers to replace troublesome drawers in the kitchen. My plan is:

Solid wood sides and back and front
Dovetailed corners
Baltic Birch bottom, 3/8
1/2" clearance under bottom for Blumotion slides
Use Blumotion slides with soft stop, regular duty ($22 each @ WoodworkersExpress (http://www.woodworkerexpress.com/Undermount-Slides/#rfplist)) rather than HD ($38)
Re-use the existing oak drawer fronts (they match the rest of the kitchen).

Currently:

Face frame construction
Full-extension side mounts
Drawers are junk
Drawers are side by side, opening 5" high
Silverware drawer opening = 20.75", Utensil drawer = 13.25
Depth to back of cabinet = 23.5"

I've never done undermounts and I don't have a Blum brochure or sample in hand, so some of my questions are probably lame.

Is 5/8" reasonable thickness for the 4 sides of each drawer?

I plan to use my PC dovetail jig that I've never used
I have not selected the wood yet, but I have quite a good supply. I will have both 3/4 and 5/8, and have a planer


Is 3/8" perfectly reasonable for bottoms?
How deep? The drawer slides are 21", but the open space is 23.5" - should the drawer match the slides? Or could the drawer be 2" deeper and "full extension" means I only get 21/23 extension?
Anchor at back - Should I add 2" blocks to make the rear mounts (I don't yet know what these look like) stronger?
Should I get any guides or jigs? I will probably do more, but maybe not.

Any advice or suggestions are welcome. My ignorance is obviously quite deep!

Thanks

[Tom M King]

Get at least one set of slides to start with, and do a mock up drawer out of scrap. You don't need special jigs or guides. There are small holes drilled into the backs of the drawers. You can easily make a simple jig for those.

Rather than buy a jig for setting the slides square to the fronts for one job, just use a scrap piece of plywood. Cut it the length to fit under the top slides and use it to set with, then cut that same piece of plywood down to fit under the second set of slides down, and so forth.

Some years I might make one or two sets of cabinets, and then it will be several years before the next ones, so I always figure out what to do each time without trying to remember all the details. It only takes a few minutes to figure them out with one in hand.

edited to add: I've never used anything other than mounting slides from the sides. I usually use Poplar planed to the right thickness if there isn't plywood at hand the right thickness.

[Ellen Benkin]

design the drawers and have them made to fit the space you have. When I had some made they included all the cuts and holes for the Blum slides. Save yourself a lot of headaches.

[Jay Jolliffe]

Unless you want to make your own drawers I buy mine from Eagle Woodworking in Mass. Can't make them any cheaper than they can.You can get all hardware from them also very reasonable. I've probably have bought over 100 drawers from them & never had a problem...

[mreza Salav]

3/8" bottoms are waaaay overkill. 1/4" is more than enough for 50kg pots & pans drawers.
Do a sample. Best to work in mm for everything.

[Peter Quinn]

No, you cannot make your drawers deeper with blum undermounts, they have to be 21" front to back of drawer (or the correct depth for the length of slides you are using). Pull the spec sheet from the blum site or a good hardware supplier, read it carefully, its all there but there is so much there its tough to filter what you need. The jig to place the rear holes and clip holes is great, but its like $55, plus drill bits, etc. I made my own from plywood in 10 minutes for about $.59. So skip the jigs, you are better off buying the drawers than all the jigs they sell. I use 3/8" on heavy drawers that are wide, deep and carrying things like plates or pots. A good 1/4" plywood is more than sufficient. That said I'd rather go over kill than use something like 1/4" 3 layer luan core junk that will sag over time in a silver ware drawer. So use your judgement there. Less harm in going over than under. 5/8" sides are pretty standard, last place i worked used 1/2" to maximize interior space, a 1/2" of solid maple is more than enough until the drawers get huge. On drawers the size you are making its your call, either size works fine.

I don't use back anchors, I'd rather pack out the side of the case and treat it as flush mount, none of the packing is visible with drawers in place, it makes a stronger connection.

[Ed Edwards]

Doug,
For good prices and GREAT service, I couldn't beat A&H TURF http://ahturf.com/store/image/data/logo.png

No association I just like um

Ed

[Jerry Miner]

We use Blum undermounts all the time




Is 5/8" reasonable thickness for the 4 sides of each drawer?


Perfect (you don't gain any interior space with 1/2" material---you only get a bigger gap between drawer side and cabinet opening)



Is 3/8" perfectly reasonable for bottoms?


Perfect


How deep?


Blum spec. is 21"---we've found that 21 1/16" actually works a little better (better engagement of the tab in the back hole)


Anchor at back


Agree with Peter. Pack out the sides instead.


Should I get any guides or jigs?


Don't bother. Get the spec.s, though, for the notch and drill in the back.

And pay attention to the offset from front of cabinet (3mm)

[Doug Hobkirk]

We use Blum undermounts all the time

And pay attention to the offset from front of cabinet (3mm)

Well thank you Jerry (and everyone else). The answers and tips - "21 1/16" and "3mm offset" - are great. When I've got the slides in hand I will read carefully. But I asked here because I wanted to know if there was anything else I should be ordering or asking about.

As usual, you Creekers have been very helpful.

[Steve Jenkins]

Actually, if you really need the extra depth you can get it. I recently needed to just that for a special application. I did it by gluing a spacer block 1/2" thick to the drawer bottom thus setting back the latching device. It worked fine. I haven't checked but I think that 5/8 is the thickest you can use for sides.

[George Bokros]

Actually, if you really need the extra depth you can get it. I recently needed to just that for a special application. I did it by gluing a spacer block 1/2" thick to the drawer bottom thus setting back the latching device. It worked fine. haven't checked but I think that 5/8 is the thickest you can use for sides.

I think you would also have to set the drawer slide into the cabinet deeper (not mount it to the face frame at the front end) in order for the set back locking device to engage the slide.

The reason you cannot make the drawer deeper than what Blum spec's is the engagement tab at the rear of the slide.

[Nick Lazz]

I haven't checked but I think that 5/8 is the thickest you can use for sides.

No flame here, but that isn't accurate. Blum makes two standard sizes, one for 5/8" (actually 1/2"-5/8") sides and one for 3/4" sides. This is indicated on the slide by the 'F' for 3/4" and the 'H' for 5/8"....that is assuming you are talking about the Tandem.
Also, although it is not necessary as some have mentioned it could save you some headaches, the Tandem Template is inexpensive and ensures accurate drilling for the necessary holes on your drawer. Any slight misalignment in angle or placement will affect the action of your slides. Ask me how I know :)
Plus it does speed up the process...especially if you don't do it everyday.

Nick

[Steve Jenkins]

I think you would also have to set the drawer slide into the cabinet deeper (not mount it to the face frame at the front end) in order for the set back locking device to engage the slide.

The reason you cannot make the drawer deeper than what Blum spec's is the engagement tab at the rear of the slide.

Good catch on the set back and face frame. I don't use face frames so kind of let that slip. Yes the spacer needs to be sized so the rear tab will engage. If you want to mount a 17" drawer on a 15" slide the spacer just needs to be 2" X 1/2" thick. It doesn't need to go full width of the drawer, you can use one on each side.

[larry senen]

my advice is wait until you can get the new Hettich slides. they are going to put blum off the market.

[Lloyd McKinlay]

my advice is wait until you can get the new Hettich slides. they are going to put blum off the market.

Can you elaborate? I'm not familiar with the Hettich brand, how are they superior to the Blum? I will be doing our kitchen cabinets soon and will be looking for the highest quality slides.

[Doug Hobkirk]

Well, this thread took on more life than I'd expected. FYI, I ordered 2 sets of the Blum 19" undermounts for 5/8" sides.

Then, FOOL THAT I AM, I clicked some more an learned about the Blum Tandembox. Much simpler to build. But metal? I like wood. But I discovered that I could get them 22" deep, which is a big deal. So I bought 2 sets of those also (gray, 75#).


I will use the undermounts on another pair of hurting drawers, unless the Tandembox seem so superior I return them
I think the Box will gain an extra 3 5/8" of interior depth (22" vs 19" plus the only front panel on the Box is the drawer front outside the face frame). That's 20% more interior space. (I know the Box interior is 15/16 shorter than 22)
Price

The 2 undermounts cost $53 including shipping.
The 2 boxes cost $145 including shipping.
$27 per drawer vs $73 - OUCH! Typing these prices next to each other, I am forced to keep repeating: My wife will absolutely LOVE the extra 20% of space!


I rummaged through my wood and discovered I have less thin (5/8) stock than I'd expected. I've got enough oak for 4 drawers and plenty of 1/4" good plywood (although a lot more 5/8"). But I've got quite a lot of 3/4" oak and maple, and a planer, but I think I'd get the hardware to fit 3/4 rather than planing it down.


In any circumstance, I will learn and next time maybe I can answer questions about Blum drawer systems!

Thanks again.

PS - I hear the suggestions to buy pre-made drawers. But this is a Christmas present, so time is short, and I already have the wood. I am looking forward to building the drawers, although I get bored after I've learned how to do something, so my labor time might also figure into future calculations.