Tell me about molybolts. I am trying to put up a shelf mounted to drywall. I feel the molybolts deemed “short” should be adequate when engaged to lock against the backside of the wall. But, the dang thing doesn’t seem to have enough room to open. But, molybolts deemed “long” seem to have too much of a neck (above the area designed to fail and scrunch). The neck seems to be significantly longer than the drywall is thick. Has anyone run into this? My gut instinct says the longer one will do the trick, but it’s a pain to try and remove if I’m wrong!
Last: (A) Why are all molybolts (that I have seen) marked 1/8"? Whether deemed “lond”, “short”, or “extra-short”…they’re all marked 1/8". What is does this refer? (B) Using a strip of paper, I am going to measure the wall thickness. Maybe this will help a SDoper advise me as to what molybolt will do the trick.
(To be posted soon…)
It’s supposed to expand into the wall, not open behind it. Toggle bolts open behind the wall. Anchors and molly types burst open and expand into the drywall.
Actually, I confused myself reading that. Mollys should open behind the wall.
If you really want something that will open behind the wall and you doubt molly anchors for some reason, go for toggle bolts.
1/8" seems to be the thickness/gauge of the screw.
Drywall does come in sizes thicker than 1/2", so you might want something that opens behind a 5/8" or 3/4" wall.
You’re saying the molybolt does not “sandwich” the sheet drywall? You’re saying when the molybolt bursts open, it should be biting into the gypsum? That’s hard to picture! From experience, it seems the head of the molybolt will first lose its grip from the wall surface and try to turn with you - as you keep trying to tighten the molybolt. Ultimately (when forced to keep turning), the head of the molybolt will route a hole big enough for the whole molybolt to push straight through the wall!
I thought the two little teeth on the head of the molybolt are to hold it snuggly against the wall surface (facing you) while the back of the molybolt bursts open as you turn the screw tighter and tighter - hence compressing the section designed to fail - and sandwich up against the back side of the wall. - Jinx
First, I took a thin strip of paper, stuck it in a hole in the drywall, and aligned it to span the thickness of the drywall, marking the near end of the strip accordingly.
Then, measuring the paper, it seems my drywall is 1/2" thick.
Anwyay, tell me more about toggle bolts as I have never worked with them. I know, you’re gonna say just squeeze the toggle piece closed, slip it through the hole, and voila. But, how do you hold the bolt still AND screw it in to tighten up snugly against the wall? Seems to me you are trying to press on the screwhead with a screwdriver, so the screw (a) won’t stay still and (b) you might even push the screw right through the hole! Oops!
So, how do you handle a toggle bolt to hold it snug while tightening with the screw driver? Do you hand-tighten until it is snug enough for a screw driver to finish the job, perhaps? Please enlighten me on such a seemingly simple thing!
Thanks,
You’ve basically got it – you can read my explanation or skip to the end where I include a helpful diagram URL.
Molly bolts are designed to work by friction when used in masonry. They expand–imagine blowing up a balloon inside a PVC pipe and then trying to pull it out. A toggle bolt, on the other hand, is more like Batman’s grappling hook, a dog’s genitals, or a barbed harpoon – it goes in tiny, becomes bigger than the hole it’s in, and then is stuck there.
A Molly bolt, because it’s designed to expand outward with such force, is likely to rip puckered seams in your gypsum unless you pick one with the right size sleeve (so that the Molly’s sleeve is the same length as the gypsum’s thickness). If you do pick the right size Molly, it basically serves as a toggle bolt.
I reviewed the link provided by Jurph, and I don’t see the difference between a molybolt and toggle bolt, in the end. Also, this diagram does not show a friction fit for a molybolt, but a “sandwich” fit as I suspected. Anyway, I still have not found an answer to my molybolt problem.
Basically, why are the short molybolts (with just shy of 1/2 neck) not tightening up…and apparently barely opening up (expanding)…and yet long molybolts have too much of a neck above the section designed to fail!
What do I do? Make shims to offset the difference and then use the long neck? I don’t recall ever having so much trouble with molybolts before now! - Jinx
Personaly I find molybolts to be a PITA for use with drywall. The problem is that when you go to screw in the screw to colapse the anchor it tears loose the drywall around the hole. This is becasue the torque required to colapse the anchor is greater than the torque required to strip the hole. :smack:
Toggle bolts are way easier to use. You drill a hole large enough to allow the colapsed toggle to pass though. You place the bracket or what ever you are mounting on the toggle bolt and screw the toggle on the end. Push the toggle through the hole, and once the end of the toggle is beyod the wallboard, the two wings expand. Pulling the toggle back slightly will cause the wings of the toggle to jam against the back of the wallboard. Holding the bracket, screw the screw in until everything is tight.
But something that I have come to love lately this anchor. Basicaly it is a large screw shapped plastic anchor. You screw it into the wall, using a phillips screwdriver. Then you use the suplied screw to anchor whatever to the wall.
NOTE: While these anchors say that no predrilling is necessary, I find it handy and easier to predrill a small hole first. This makes the anchor easier to install, and helps you indentify if you are installing into a stud.
Molly anchors (moly makes many of us think molybdenum) are indeed thickness specific. When used in drywall, many types do not require predrilling-tap the pointed end through the sheetrock and then run down the screw. Readily available drywall dimensions are 3/8", 1/2", and 5/8". Some people put paneling over drywall, hence the need to accurately ascertain the dimension of the substrate to which you are applying a fastener.
A toggle bolt is shoved through a clean hole in the drywall, as is a butterfly or wing bolt, both being tightened with the fixture in place. Take them apart, and the end inside the wall goes to the land of lost left sox.
Togglers (which was a Sears brand name) are plastic anchors which are driven into drywall and then forced to spring open, using a little red button/shaft tool. These are also wall thickness specific.
This should clear it up…shows all types in action:
http://www.oldhouseweb.com/stories/Detailed/10117.shtml
(For togglers…just turn and keep a slight pull to keep the back firm against the drywall…eventually, it will be set enough to turn with a driver…often with the weight of what you’re hangin’ to keep it snug. )
Well now, if I were mounting a shelf to carry any weight at all, like books, in the kitchen or other utility area I would get a clear piece of 1 X 8 pine and fasten it to the studs with screws at least 2" long. I would put three screws in line in each stud and I would fasten to every stud over the span of the shelf. Then I would fasten the shelf supports to the pine board. For a living room or other “nice” area, substitute some hardwood, maple, oak, etc. for the pine. Expensive but worth it.
Sounds like a nice suggestion, but can I ask…what is a “clear” piece pine? Maybe it was a typo, and you meant “clean” piece of pine (sans many knot holes)? - Jinx
a) Yup, that’s about the size of it! One of my problems with molybolts, in recent years. Used to always have success, though. Maybe the fastener industry is losing its QA, like everything else in this world.
b) Using Toggle Bolts: There is another problem with toggle bolts. When you drill this massive hole wide enough to pass the “butterfly wings” of the toggle through, often the bracket is not even wide enough to hide the hole! I guess you then need to find a washer that is (a) of a large outer diameter AND (b) of small inner diameter…so the screw head retains the washer! It is another royal pain in the ass to find such a washer! I have a zillion spare washers stored away, but few that meet both criteria! Any other suggestions? (Get a wider bracket, right?)
Sheesh! We can send a man to the moon, but don’t ask him to hang a damn shelf!
In lumber “clear” means without knots. If there are knots you need to paint them with some kind of sealer or the paint will discolor over the knot sooner or later. Shellac used to be used as a sealer but I suppose there are now some acrylic plastic finishes that will do the job.
