Replacing Stripped Thread Inserts on Wooden (MDF) Tabletop for Legs

bombardier

Hey guys, I have acquired a new table but one of the legs needs some repairs. As you can see in the pictures, the previous owner tried to repair it themselves with some small screws, but I intend to try and repair this to more original quality standards. The tabletop is very heavy for the size, so I'm guessing it's made of MDF.

I tried installing some new thread inserts but the laminate had definite damage from the previous strain, and around the 3 stripped holes the tabletop material is bulging slightly (you can see in the below pictures), so the strength is somewhat compromised even though the new thread inserts I bought have larger outer threads.

First picture is of the thread inserts that used to be in these holds (left, brass coloured) and the new ones that Home Depot carried, as well as the bolt/washers I have (I had to buy those, they couldn't find the originals). They are the same thread size (5/16") and the same diameter at the widest end. The old ones are of a tapered shape, the new ones have a slightly larger thread diameter overall.

http://i.imgur.com/W44J4.jpg

The second and third picture are of the damaged holes.

http://i.imgur.com/t5TN2.jpg

http://i.imgur.com/1oyjx.jpg

Fourth picture is of the holes and the table leg assembly. Moving the holes is an option I would take if necessary, but I want to know if there is a way I can repair the existing ones.

http://i.imgur.com/4wD8u.jpg

Fifth picture is of the good thread inserts. I can't quite tell if the laminate is covering up some sort of dowling insert or what, but these don't quite look like they're directly into the tabletop material.

http://i.imgur.com/A8kdd.jpg

After viewing this video, I realized I was an idiot trying to install the new thread inserts with a flathead screwdriver:

http://www.youtube.com/watch?v=tIhEqoKE8Dc

Tools I have: power drill, drill bits up to 1/2"

I live in an apartment and don't have access to a workshop, but I can acquire new tools or drill bits like hole cutting bits if needed. I also need to get a 5/16 bolt and some nuts so that I can install the new thread inserts properly as shown in the above linked video.

What should I do? Move the holes? If so, does it seem like the original thread inserts are just screwed straight into the tabletop material? Is there some other good way of repairing this type of material? Get bigger thread inserts and drill out the holes?

LewieP's Mummy

OK, I can't tell from your pictures if the holes go through the table completely or if I'm just looking at the underside. I'm going to assume just the underside, and that the holes are to hold the screws to hold the legs of the table in place. If so, I have a similar table and so can maybe help.

Your choice is to either fill the holes with wood filler, something like http://www.ronseal.co.uk/products/high-performance-wood-filler then either push the thread insert in with the wood filler before it sets, or re-drill new holes. My table has 4 cylindrical metal legs, held in place by a flat square of metal at the top of each leg - 4 screws per leg, one in each corner of the square. I've had to make new holes for the legs as they were wobbly, so i just rotated the square thing, marked new holes, drilled pilot holes, and then went for it. Its not that hard, you don't need lots of tools like the bloke on the video did. Get a http://en.wikipedia.org/wiki/Bradawll to make your pilot hole, then measure the depth of the thread insert, mark it on your drill bit with some tape so you know how far into the table base to drill, drill the hole and bob's your uncle!

illig

the particle board furniture is usually weakly constructed - are you even sure if the rest of the table top has solid material throughout rather than just a veneer? if it's empty inside (or filled with styrofoam for example) then your idea of redrilling the holes would not work

could you consider just using a larger bolt and securing it through the table top? would that destroy the look of the table? that's what i did on one IKEA side table and it came out quite sturdy...

bombardier

LPM: you're looking at the bottom and the holes are drilled at least an inch deep. The tabletop is actually leather-wrapped on the other side.

Oh the whole thing is solid MDF. The tabletop is about 2.5'x5' and 2" thick, so it weighs maybe 70 pounds.

Redrilling the holes for new thread inserts shouldn't be a problem but it's something I don't particularly want to do. For the existing holes I'm thinking of getting larger thread inserts and then drilling the existing holes out and using some slightly bigger diameter bolts.

mts

just drill out the old holes and throw in the larger insert, that is going to be the easiest, you be able to find larger inserts with the same inside hole diamter saving you the effort of finding bigger bolts

LewieP's Mummy

Still pack the holes with a bit of wood filler, and drill new ones, as the holes in the MDF look shaky at best; that way, you won't put the MDF under more pressure. And, pics when you've done it, please!

bombardier

Ok so I actually ended up drilling new holes, because well, the previous people already made a mess of it and I'm never going to look at the bottom of my table. I would have had to drill out the holes pretty large to get rid of the buggered MDF from the old inserts being torn out so I moved the holes 1.5" to the side and got some slightly longer bolts so they're not sunken into the wood (I would have had to buy hole cutting bits).

Home Depot had some larger inserts but I didn't want to use larger bolts, @mts they didn't have any larger inserts with the same sized bolt threading unfortunately. I was hoping they would but alas. I DID get a 6" bolt and cut off the end and used it to install the new thread inserts like the youtube video showed and it worked beautifully. I had to drill out the holes larger than expected because the material started to bulge out a bit.

Thanks for the suggestions though! It got me thinking at least. Here's some photos of what I ended up doing and the table set up. Not bad for about $70 and a few hours work.

I miss having a workshop.