Another quick question

[phrog]

When cutting MDF which is grainless, there's no such thing as ripping or crosscutting.

Oh yeah. I forgot that MDF has np long fibers. But sharpness is almost a necessity.

[PartTimeHack]

Ah, yes. I forgot that ripping and cross-cutting had more to do with grain direction than geometry.

Sheepishly I was going to use MDF for the cleats. It was stock I had and the flatness/thickness uniformity was appealing. At 3/4", and roughly 6" (entire cleat joint) deep it seemed like it might work. With the cleats being around 18"-24" long, it gives me at least 4x (2x at each stud) 3" long coarse thread screws to mount them.

Do you believe the softness of the MDF would have a tendency for the screws to eventually pull through and I should go with 3/4" ply instead?

A side note:

You know of a decent stud finder? I have had an old Stanley for more than 10 years. When it works, which is about 1 out of 10 times, it works well. I have "nicer" Stanley with a laser, and it works every time I press the button...however, it's stud-finding capabilities are absolutely horrible.

[lrr]

Ah, yes. I forgot that ripping and cross-cutting had more to do with grain direction than geometry.

Sheepishly I was going to use MDF for the cleats. It was stock I had and the flatness/thickness uniformity was appealing. At 3/4", and roughly 6" (entire cleat joint) deep it seemed like it might work. With the cleats being around 18"-24" long, it gives me at least 4x (2x at each stud) 3" long coarse thread screws to mount them.

Do you believe the softness of the MDF would have a tendency for the screws to eventually pull through and I should go with 3/4" ply instead?

A side note:

You know of a decent stud finder? I have had an old Stanley for more than 10 years. When it works, which is about 1 out of 10 times, it works well. I have "nicer" Stanley with a laser, and it works every time I press the button...however, it's stud-finding capabilities are absolutely horrible.

I like MDF when flatness is a consideration (like multiple layers for a cheap workbench top), or for cabinets that have a hardwood veneer, so it will be dimensionally stable. But you do not want to put it under a lot of stress, and cleats with screw holes sounds less than ideal. I'm not exactly sure of your exact use of the cleats, but I'd be more inclined to use pine or plywood if possible.

Since MDF is so hard on blades, I've bought bargain carbide blades to use to cut MDF -- a midrange combo blade with around 40 teeth. Sharp blades are way more important than blade pedigree -- buy a bargain blade at Home Depot and use it only for MDF.

I bought a Zircon stud finder last year, and it is great. It has a LCD display that shows you the stud's proximity, and "paints" an arrow on the wall to show you where to mark the wall. The new stud finders are self-calibrating. I replaced an ancient model from Sears that required calibrating using a thumbwheel. Some poor sucker got mine from Goodwill probably, and is cursing it every time it is used ... Zircon has several models, and mine was maybe not the cheapest ($25), but definitely not the most expensive ($50 or more, and can detect metal and other wall obstructions).

[LCHIEN]

I think a thick piece of MDF screwed to real wood will be under compression and all right.
I'm not sure I would use it where I have a screw into the MDF alone holding a load.

FInally I think that the 45 degree edge would not fare well - where you are depending upon it to hold the entire weight of your cabinet from falling off the wall.
It would not have the strength to keep from crumbling and breaking off under any wear.

[LarryG]

I've not had a problem with French cleats made of MDF, as long as the anchorage to the substrate is secure.

About six or seven years ago I was commissioned to build some open-front wall-hung storage bins; about 18" deep by 18" high and heavily loaded (fabric samples). It's been a while since I've seen them but AFAIK they're still doing fine.

ETA: Rereading what I posted, it sounds like I'm dismissing the concerns outright, when my intent was only to share my own experience. If the units being hung from the cleats were being moved around a lot, then the edge crumbling might well be a problem and the cleat edges could deteriorate from being knocked together repeatedly. For a hang-it-and-leave-it scenario, it seems to me that the two halves of the cleat go back together and act as a single piece, and with the load being distributed firmly and evenly there's not much chance for failure, short of the whole thing being pulled off the wall.

Also, thinking back, these particular units may have been more like 14" deep rather than 18" but, as I said, they were still carrying a pretty big load.

[PartTimeHack]

I'd like to say thanks to all who contributed to this topic.

After reading them, I decided to use 1"x4" furring strips cut in roughly 3'6" to 4' sections (depending on space and stud spacing). So far I've gotten about 4 studs' worth, or 8x 3" screws holding the cleats.

I also bought a Zircon stud finder. Works well so far.

As far as the progress, I hung the corner cabinet and 1 adjoining cabinet a little while ago. It looks like it will work fine.

Side Note:

The cabinets were installed by the original homeowner about 20 years ago in the garage. He basically hung them by screwing in 2"x4" strip horizontally at the top and bottom so he didn't have to find the studs, then screwed in another 2"x4" at a right angle underneath as a support. I never liked his method. Not only was it ugly, and spaced the cabinets out unnecessarily, he also stripped out almost every screw head...as if he were doing it on purpose. I actually had to buy a screw extractor in order to remove the cabinets and all the 2x4's!!!

The cabinets aren't the best quality construction even though they were purchased from a cabinet shop. The sides, tops, bottoms inside cleats and shelves are 1/2" particle board. The front facing and doors are solid, and the back panels are 1/8" hard board. Except for the corner cabinet, which had extra material on top for mounting the French cleats, I'm having to cut and install some reinforcements on the rest. It's a good use for the Kreg jig at least.

Having said that, putting up those first couple of cabinets in the shop has been satisfying. Dang things are actually fairly level too. The best part is if I don't like where they are, I can hopefully reconfigure them fairly easily.

Again, I appreciate all the input.

[phrog]

he also stripped out almost every screw head...as if he were doing it on purpose. I actually had to buy a screw extractor in order to remove the cabinets and all the 2x4's!!!

Sounds like a lot of fun.

[JimD]

Sounds like the screws might have been driven by a corded drill and by someone who wasn't very skilled. That would be consistent with the support.

Free cabinets are always worth a try but your description of the construction makes me happy I will make my own out of 3/4 plywood.

I've used studfinders over the years but I usually just use a nail to find a stud and then measure out on 16 inch centers and check. Often you can hide the nail holes when you hang the cabinet. A 16 gauge pneumatic nail makes a small hole but is sturdy enough to work.

[PartTimeHack]

I'm also guessing the previous owner had some aversion to drilling pilot holes and just tried to use raw power to force them in. It's one of my pet peeves.

The cabinets don't use the best materials, but they are surprisingly sturdy. They are 20 years old now and aren't any worse for the wear.

I needed to get something on the walls so I could get the ton of stuff off the floor and out of my way. Having a small shop is bad enough, but tripping over everything is frustrating.