Downside to screws for enclosure building??

[rogerh113]

Hello,

I am planning to use some thin, long screws to put my enclosure together (with glue, of course). The Altec enclosure was originally secured with quite long brads, but I am assuming those were used because they are faster than screws. I have seen some threads that say 'don't use screws', but it is unclear why that is the case, or if it is a matter of preference or an old wives tale. In any case, I simply don't have enough long clamps to manage everything with out taking advantage of screws (or brads) - the holes are there, and it seems a solid approach.

Any reason why I should not use screws, or any precautions I should take when installing the screws?? I gather some are concerned with them 'backing out' over time. The material is vintage Altec plywood, and so it should be very stable (after 20 or 30 years)....

regards -- Roger

[Elitopus1]

I have heard the same thing about not using screws. I am curious what the reasoning is behind it. Most of the OEM cabinets only have screws to hold on removable panels. And like you said they used glue and brads for the rest.
I am curious to hear the responses to this thread. Maybe I can finally start building my cabinets the right way

[GM]

Screws create 'hot spots' [high rigidity, hence brittle] with only localized clamping, so unless they are relatively close together and properly installed/torqued based on the material specs, best to limit them to properly gasketed/installed removable panels where the gasket can average out clamping/reduce the torque required, though fine for general construction if used with cleats that are preferably spanning at least ~71% of the internal [i.d.] length, leaving the corners open for just glue: http://www.lansingheritage.org/image...ign/page18.jpg

Example of relatively poor use of screws on these [repurposed] cabs done before getting OJT [on job training] of the subject: http://www.hometheatershack.com/foru...ltec-subs-.jpg

Enough screws due to erring on the side of caution, but none should be in the corners!

Note the screws are inside, not through, the Nema 4 [5-12 and 3R is fine too] neoprene gasket [a big time no-no for removable panels unless it's wide enough to have plenty of 'meat' on either side, i.e. won't squish out on either side once tightened]. These were built in the late '60s and still seal well with original gasketing after annual driver rotations to redistribute its surround goop.

Note too that as it turned out, there's exactly a boxful [144] of countersinking wood screws holding the 2x4, 2x6 framework and 3/4" marine grade panels all together with whatever wood glue was popular back then [Elmer's?].

In short, for the most part the kind of 'good' engineering typical of an ignorant one.

GM

[mah]

I used 4 clamps similar to these:

http://www.harborfreight.com/hand-to...amp-96208.html

[GM]

Hopefully better constructed , as noted in customer reviews the bar flexes way too much for any serious clamping and even my much sturdier, ancient 36" Jorgensen 3736 bars have trouble dealing with warped Southern Pine, so use this type pipe clamp for > ~24", though contractor grade with 3/4" pipes up to 12+ ft long: 1/2" Pipe Clamp

GM

[Elitopus1]

I need to get some of those pipe clamps. Thats a good deal

[mah]

My clamps are 30 inch, Topmax brand. The jaws fit the bar(20mm x 5mm cross-section) snugly. External clamping puts the bar in strong tension so buy ones with sturdy jaws. They did the job OK.

Pipe clamps are a better and affordable option if you can buy the threaded pipe locally or have some scrap pipe and access to a threading die and suitable vise.

Clamp pressure? It depends on the material, type of joint and the adhesive.

[RonSSS]

I'm screwed.......

I added bracing to my M19's....yes on the inside.
Elmers glue and wood screws.

Worked quite well. The boxes now pass the knuckle/fist test.

Anyway, I'm screwed......

[rogerh113]

Hello,

Thanks for all of the input. It sounds like there is a good reason not to use screws. My current thinking is to just use glue, with screws only for the removable back. I will have to come up with a way to build up the cabinets in pieces (not all in one shot), or round up more clamps. Hopefully if I build the components carefully, and dry-fit carefully before I start assembly, a staged assembly will not be a problem.

I rarely do woodworking, so getting more clamps will just fill the garage with more stuff I rarely use.....

regards -- Roger

[endeeinn]

Anyway, I'm screwed......

Me too!

Carpenter's glue, screwed and clamped with pipe clamps. Interior as well is heavily braced as well glued and screwed in place as well as screwed from the outside where possible. Been that way for 20 years or so with no problems and it still passes the 'knuckle test'.