Drilling Blinds into French Door

roysterfamMarch 17, 2011

Hello all, been a fan of the site, but this is my first post. I'm having a problem. I ordered some new shade blinds for my french doors in my basement. I'm trying to drill the brackets into the door, but I'm not sure if I have the right drill or drill bit.

I'm sure I have the wrong, or a cheap drill, its a $20 9.6v Durabuilt drill I purchased from Target. And I'm not too familiar with drill bits but it looks like a regular black and grey 1/8 bit to me.

Any help?

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Sorry for the follow-up, but I think it's a shallow door, maybe some kind of foam or something I guess. Is there something I can use to strengthen the screws into the door? Thanks.

    Bookmark   March 17, 2011 at 12:54PM
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What material is the door? Is it a hollow wooden door, a hollow metal door, a hollow fiberglass door?

    Bookmark   March 17, 2011 at 3:11PM
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There are methods to anchor in hollow or foam filled doors, but you need to know how the door is made before choosing.

Molly bolts work pretty well in hollow or foam filled doors, but can be a chore to set without a setting tool (just using the screw) since the teeth are not likely to dig in well when you try to expand the anchor.

Plastic type expansion anchors will not hold at all.

    Bookmark   March 17, 2011 at 5:12PM
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I think its a hollow metal door. I actually used a (again, I'm not familiar with bit types) gold bit to pre-drill a hole in the door. But like I mentioned, its not holding tight to the door.

What are molly bolts, I heard of those. Would I use those with the screws that came with the blinds? Or are they they're own application? Thanks

    Bookmark   March 17, 2011 at 5:56PM
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Molly bolts are expanding metal anchors for thin surfaces.

They spread out behind the surface as the screw is tightened (or pulled by a setting tool) to spread the load out over a larger area.

Here is a link that might be useful: Wiki on Molly fasteners

    Bookmark   March 17, 2011 at 8:34PM
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Hi, I don't believe molly bolts are the solution to your problem. You have to drill too big of a hole and they have to go too deep to install.
The 1/8 bit may be too big. Try 1/16 you can always work up but its realy hard to make a hole smaller. If the screws fail then drill a 1/8 hole and use a pop rivit. I installed blinds on my metal door with screws and had no problem. You can patch the old holes with either caulk or epoxy.
Good Luck Woodbutcher

    Bookmark   March 18, 2011 at 7:24PM
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Thanks for the advice. I guess I should've stayed with what you all were telling me, but none of the stores in my area seemed to know what molly bolts were, until I already messed up my door. I have to buy another one now.

The guy at Home Depot sold me some hollow door anchors, and of course, they didn't work. Then someone at Ace sold me some sheet metal screws, and of course, they didn't work. Now at least one of my french doors is ruined, to which I have to get another one.

I should've stayed with you guys and not been so haste to hang up the blinds for the ol wife. Thanks anyway

    Bookmark   March 19, 2011 at 1:25AM
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It's not my intent to be mean, but this is the most basic do-it-yourself project. Since you are having trouble with this you need to get a handy friend to help you. This is not the type of project that should result in having to buy a new door.

    Bookmark   March 19, 2011 at 3:30AM
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Actually, I'd disagree with this being a basic project. Screwing into a hollow/foam filled door can be tricky for the beginner because the steel is so thin or the fiberglass so soft and both are unforgiving. Wrong size pilot hole or over driving the screw will lead to trouble.

When using sheet metal screws it's critical to drill the correct diameter pilot hole. The pilot hole should be the "root diameter" of the screw. Although this is a picture of a wood screw the principal is the same and the root diameter in this illustration is "R".

When starting the screw, it's important to drive with enough force, especially if you're using a drill as the driver. Too little pressure and the screw will act like a drill bit, enlarging the pilot hole. As the screw comes into contact with the metal (or backet in this case) it's also important not to over drive the screw because that will also enlarge the hole creating holding problems. That's even more important in something like fiberglass because it's soft. There's a bit of learned skill in this operation. If the hole is enlarged the only option is to use the next larger size screw.

It should be noted that residential hollow or foam filled doors typically have wood at the edges (1 1/4") so the there's someway to attach the hinges and lockset. If at all possible it's best to hit the wood, at least with one screw of the bracket.

Molly bolts are a good way to go too because they provide a lot more holding power because the "wings" of the bolt expand when the screw is tightened.

Molly bolts are typically used by drilling a pilot hole, inserting the molly into the hole, and tightening the screw to expand the wings. Once tight, the screw is removed and then reinstalled with whatever item you want to hang. The illustration shows little "teeth" on the underside of the head. Those bite into the surface to keep the molly bolt from rotating as the screw is tightened to expand the wings.

With a steel door, there's nothing for those "teeth" to bite into so a "setting tool" must be used to expand the wings. Setting tools won't be found in the typical hardware store or home center but they're usually under $20 and quite useful.

The illustration of the molly bolts above are not the correct ones to use for a hollow door (the long, smooth part below the head is the clue, that's for much thicker surfaces like drywall). I couldn't find a really good picture of what is needed but here's what I could find.

There's little or no shaft below the head. They're also much shorter.

When using a molly bolt, the screws included with the bolt are what is used to mount the hardware.

    Bookmark   March 19, 2011 at 7:39AM
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Well yeah kudzu9, I am a beginner Di'yer. I know building the occasional Ikea item doesn't necessarily make me a pro. But I'm not familiar with molly bolts, and the main chain of hardware stores wasn't familiar with it either, so it left me to try other applications.

Thanks mike_kaiser for clearing up the difference in the screws. The sheet metal screws I used was for a slightly bigger hole that I had already pre-drilled for the brackets, so they didn't work. I was trying to avoid more holes in my door. And of course the hollow door anchors they suggested (because they didn't have the molly bolts) just kept spinning in the door.

But I found a website that sells the molly setter tool that I'll purchase, thats after I get a new door. Thanks again for all your help.

    Bookmark   March 19, 2011 at 9:33AM
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"Hi, I don't believe molly bolts are the solution to your problem. You have to drill too big of a hole and they have to go too deep to install. "

As long as you select a molly that is short for thin surfaces it will be well less than the door thickness.
The foam is usually soft enough you can drill the metal and just push the unexpanded Molly into the door.

You will need to bend up the small teeth (or cut them off) to get the Molly to rest flush with the surface of the door, but you have to do the same thing with plaster to prevent damage to the thin finish layer.

having used many Molly bolt in steel clad metal faced doors I can tell you they work very well.

Even sheet metal screws have a hard time standing up to the loads from curtain rods and curtains in a moving door unless the curtains are little more than sheers.

At this point there is no reaosn to replace the door, just enlarge the holes and use Molly bolts and a setting tool.

You might try a real hardware store and not a big box place.

The big box laces often do not even know the names of their products, and may have Molly bolts marked only as 'hollow wall anchors.'

    Bookmark   March 19, 2011 at 9:48AM
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I'm not dissing you...we all started out as no skill DIY-ers. Molly bolts are as common as dirt, and someone in a hardware store who doesn't know what they are either by name or description needs to find a new job.

To use them, you just need to drill the correct size hole which you'll find listed on the instructions (typically 1/4"). Make sure you are using decent drill bits, use a nail or pin punch to put a small dent in the door where you want to drill (otherwise the drill bit will wander), and start with a small bit (1/16") and work up to the larger size rather than trying to drill the hole in one go (it'll actually be easier to use several bits). Finally, when you are selecting molly bolts, read the packages carefully to make sure you get one that will grip down to 0" thickness; many of them are for sheetrock and will only grip in the range of, say. 3/8"-5/8". If you use one with the wrong grip range you will get it stuck in the drill hole and not be able to get it screwed down tight, and you won't be able to get it back out. If so, then you'll have another big problem.

Hopefully you can just enlarge holes you've already made rather than get a new door.

    Bookmark   March 19, 2011 at 3:02PM
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Thanks again. I'm going to try this local hardware store and see if they have the products. I appreciate the help.

Kudzu9 I didn't take your comment as a diss at all. I was just saying my di'yer experience only goes as far as Ikea right now.

I do think the door is ruined though, I drilled some pretty big holes in the door (using a 5/16 bit) to make room for the anchors the big chain stores told me to use. I guess I can just replace that one side of the door, and not both in the french door frame.

Thanks again.

    Bookmark   March 19, 2011 at 6:00PM
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Before you run out an spend a lot of money on a new door, a 5/16" hole should be right for a 1/8" Molly Bolt (1/8" refers to the diameter of the screw of the bolt). I'd suggest trying that before you order up a new door.

    Bookmark   March 20, 2011 at 6:40AM
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The head of the Molly bolt should easily cover a 5/16 inch hole.

As long as you use the setting tool you do not need to hold the outer expanding par of the Molly from rotating while setting it.

You are likely to need to bend or cut of the two small teeth designed to prevent rotation while setting.

Waste a Molly and expand it using the setting tool in the open so you understand what is going to happen inside the door out of sight.

    Bookmark   March 20, 2011 at 10:52AM
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Unfortunatly I caught you to late. However many people think hanging blinds is simple but you can make a very easy job difficult if you dont do this type of work normally. I do this for a living and infact my company installs over 500 blinds per week. All you need is a 1/8 inch drill bit, 1/4 inch driver and 1/4 inch screws no longer then 1' or you will go through the door and out the other side. Trace the holes of the brackets on your door 1/8 inch wider then the width of your blind on each side. Then make a little pilot hole with your drill bit. You should use 2 screws for each bracket. Then put the screws through the bracket holes into your pilot holes, go slow and DO NOT OVER TIGHTEN. If you over tighten this will strip the door surface and comprimise the integrity of the screw holding to the door. If you make a mistake you have 2 more shots at it with the other holes in the bracket. Anchors and toggle bolts may work but are not necessary.

You may also repair the holes in your door with a little puddy or caulking in the holes, sand it smooth, prime it, and then repaint the surface.

When your blinds are mounted properly it will probably cover the existing damage to your door.

If you need any help you may call me at Blind Ambitions 1-800-692-4513 ext 101 I will be happy to walk you through the process over the phone or picking out your tools, free of charge. Or I know plenty of installers throughout the southeast that I could put you in contact with that can fix your problem.

I hope it turns out great for you.

    Bookmark   March 20, 2011 at 7:44PM
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"Anchors and toggle bolts may work but are not necessary. "

Anchors are going to fail in short order in a foam core door.

They relly on exapnding agasint something more solid to hold, and foam is not exaclt y strong enough to expand against.

I have seen more blinds in metal faced foam doors pull out in short order from normal opening and closing to ever recommend anchoring on just the thin sheet metal of a foam core door. Even HVAC ducts are often thicker metal.

    Bookmark   March 21, 2011 at 8:12AM
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Hey all, thanks for all of your advice and opinions, but an especial thanks to blindambitions1, I was able to use your advice to the T and it worked out great. Thanks again.

    Bookmark   April 5, 2011 at 4:14PM
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