Confirmat Screws and Zentrix drilling system

[richards]

All of the books that I have on building frameless cabinets using the 32mm system suggest using confirmat screws for cabinet assembly when the cabinets are constructed of melamine particleboard. The 7mm x 50mm confirmat screws that I purchased require a stepped drill (expensive) and a jig for accurate hole placement. The Hafele Zentrix jig (part no. 001.22.510) has been suggested as the 'standard' for manually drilling holes. Since that particular jig is not locally available, have any of you ever used it?

I would rather use rabbits, dadoes and grooves for cabinet construction, but ALL of the cabinet shops that I've visited say that butt joints are more than adequate. All of the shops use butt joints exclusively.

Since the butt joint seems to be the preferred type of joint, the literature recommend the confirmat screw. None of the shops that I've visited use the confirmat screw, instead they use deck screws, sheet rock screws, and ordinary wood screws; however, the literature clearly states that the confirmat screw was expressly designed for use with particle board. What do you think?

[gerald_d]

Don't you have "chipboard screws" over there? We use them without a pilot hole into the edge of 5/8" (16mm) "chipboard" without splitting. Typical screw size would be about 4mm x 40 (or 45). Let me qualify that I am a DIY person for this wood application - it is not my profession and I may be doing it all wrong.

[ckurak]

Mike,

Another vote for butt joints and screws, no glue. I do not use the confirmats. I am guessing they may be handy for RTA (Ready to Assemble) boxes. Years ago, when I bought some RTA bookcases for office use, the confirmats were handy for assembly, disassembly, reassembly, etc.

Now that I build my own boxes, I use #6 x 1 3/4" ZIP-R Screws with a square drive head. (A good cabinet supply house will usually carry #8's. I like the thinner ones.) With melamine I usually predrill (with a countersink attached to the bit) so the screws do not wander and blow out the sides. (I use 3/4" melamine.) With 3/4" plywood, I skip the predrill step. The screw heads are self-countersinking. I do NOT use drywall screws, deck screws, or wood screws. The ones I use are made for this type of work.

I know the PRT can handle dadoes, rabbets, and grooves. I just found it faster to use butt joints. I don't have to worry about the thickness of this particular delivery of sheetstock before I cut the dadoes. I don't have to wait for the glue to dry. I just let the PRT drill all of the hardware and shelf pin holes, then cut out the rectangular pieces. Also, since I do "flat-finishing," finish material in the dadoes and glue won't work well. Screws and butt joints do.

Also, I might suggest that you take a look at another forum: woodweb.com. Try doing a search and you should find lots of ideas, and opinions, on the subject. For example, search for "cabinet construction" and see what you get. :-)

Finally, let me make a comment about construction. I don't believe there is one "better way" to build boxes. If you build a strong box, it fits your needs (in terms of time, look, personal preference, and it fits your system), then it is a good way. I've tried a number of methods including dadoes, several different glues, and rabbets. (Never did try dowels.) I've adopted the butt joint and screw method. This works well for me.

Good luck,

Charles

[richards]

Charles,
Thanks for the advice on the Zip-R screws. It looks like the Hafele 010.32.050 is the screw that you're describing. Is that the proper part number?

The cabinets that I'll be cutting won't require disassembly, so the Zip-R looks like it may be the answer - especially, if I can use a standard drill bit with countersink rather than buying hard-to-find stepped drills and jigs.

Thanks also for information on the woodweb.com site. I've been there several times in the past and found it enlightening; however, there are a lot of strongly held opinions posted on that site, usually with good supporting information. A lot of the time I don't have enough experience to know which of the ideas being discussed would work best for my particular application.

Gerald,
Back in 2004, before buying a Shopbot, I ran an unscientific test where I assembled some butt joints in melamine particle board using the types of screws found at the local hardware store. In every case, either the board split, the melamine cracked, the screw snapped off, or the screw stripped out of the material. I'll admit that I didn't use a countersink on the holes that I pre-drilled, which might have made a big difference in the test results. When none of the common screws seemed to be what I wanted, I tried the 7mm x 50mm confirmat screws. They worked perfectly, except that drilling a stepped hole required a jig and my homemade jig was not reliable.

When the Shopbot arrived, I simply changed my methods to use dadoes, rabbits, and grooves. Sometimes I used wooden dowels in edge-holes drilled with my horizontal boring machine. The grooves/rabbits/dadoes and/or dowels were easy to machine, but gluing and clamping made assembly non-productive.

I've even toyed with the idea of building a pseudo-shopbot horizontal-boring machine (Gecko/MachIV/etc.) to edge-bore holes with the same precision the Shopbot gives for vertical holes. But, I'm still testing hardware, electronics and software on that project.

With Ryan Patterson's free or low cost software and Pat Fulghum's free box cutter software, the designing of cabinets has been reduced to a few key clicks. Finding a method to assemble the resulting cabinets, especially the potential of totally assembling everything at the job site, opens up new marketing possibilities. What I'm wondering now is whether I can machine and edge-band the panels and shelves at the shop, machine and paint the doors at the shop, pre-assemble end-panels at the shop, and then have some other crew, using low tech hand tools, assemble the cabinets at the customer's site. If that can be done, then I've found my niche.

[ckurak]

Mike,

The screw you mentioned is a pan-head. I do NOT use that one.

I use Hafele 010.22.950. This is a Flathead Countersunk Screw. This part number is for zinc-plated in 5M quantities. I believe there is a black oxide counterpart if color is important.

Also, these screws are "case hardened for added strength" according to Hafele. In otherwords, they won't snap like drywall screws. I've broken drywall screws installing drywall. Just get an old stud on a remodel, and "snap"!

Regarding woodweb: I just kept reading and reading. As I tried things on my own, and talked to fellow cabinetmakers, I began to decide for myself which opinions and ideas would work for me.

Good luck,

Charles

[Ryan Patterson]

Mike

[pfulghum]

I use butt joints on 3/4" material.
During alignment I just pluck a couple of 1.5" staples then I pre-drill (not really necessary) and screw with #8x2 Zip-R. These screws will counter-sink itself...

Hard to beat...fast and strong.

-- pat

[gerald_d]

Around here the guys don't countersink either.