Broken screws :(

[neepheid]

As some of you might know, I'm in the middle of restoring a 60s Hagstrom bass. I've hit a wee snag - broken pickguard screws in the body - in 3 places. One of them I can see the top of it flush with the surface, the other two are broken further down the hole. I'm thinking I might be able to very carefully grind a slot in the top of the one I can see using the dremel and screw it out, but what to do about the others?

Anyone got any ideas? The whole thing is being refinished a solid colour, so the solutions need not be pretty, as long as they won't show on the finish.

[The Burpster]

Realy the only way is to get a very narrow center punch down the hole to the top of the screw. Punch it and then drill it carefully and then use a stud extractor.....

VERY time consuming to do it right.

Failing that, Drill them out MUCH larger (say 3mm or so) and plug teh hole with 3mm dowel. finish teh top of teh dowel so that when re-finished you cant tell the plugs are there.

[geilerbass]

I'm sure I remember reading on talkbass about removing screws. I think you should be able to use something like [url="http://www.google.co.uk/products?hl=en&q=screw+extractor&cr=countryUK%7CcountryGB&um=1&ie=UTF-8"]this[/url], though will probably need a very small drill bit to get in there in the first place.

Broken screw heads have to be amongst the most infuriating problems ever to be encountered...

[neepheid]

The problem with extraction is that the screws in question are very small (longer and thinner than your usual pickguard screws)

Will probably have to drill out. I have some 3 and 4mm hardwood dowel, so it looks like the brute force approach is the way

While doing some online research, I came across this - interesting use of brake line (basically making a tiny holesaw out of it):

[url="http://answers.yahoo.com/question/index?qid=20070910053127AAp277A"]http://answers.yahoo.com/question/index?qi...10053127AAp277A[/url]

[Peaty]

Hmmm drilling out with an ordinary but larger drill bit is not good as the bit will tend to slide of into the softer material ie the wood. I have had some success milling out the ends of SMALL broken screws using a diamond tipped modeling burrs such as these

[url="http://www.axminster.co.uk/product.asp?pf_id=21887&name=diamond+bits&user_search=1&sfile=1&jump=0"]http://www.axminster.co.uk/product.asp?pf_...le=1&jump=0[/url]

I used a small modeling drill rather than a dremel as i could not adjust the dremel to run slow enough to be accurate

good luck

Edited May 21, 2008 by Peaty

[ahpook]

how about epoxying a length of steel rod to the exposed screw and then using a pair of pliers when it's set.

[budget bassist]

[quote name='ahpook' post='203686' date='May 21 2008, 01:02 PM']how about epoxying a length of steel rod to the exposed screw and then using a pair of pliers when it's set.[/quote]
Now THAT'S a good idea, i might give that a go, i sheared a bridge screw in my tobias not so long ago (ouch ) and i haven't had the balls to try and get it out as it could mean REALLY messing something up.

[neepheid]

Drilled out the two that were broken down in the hole somewhere, the drill had an existing hole to follow and drilled right into it and some metal filings later, I can fit the screw down the hole. Glue, dowel, mallet, wait, cut, sand, redrill.

Unfortunately, Peaty's prediction about the drill sliding came true with the one that was flush with the surface, but I've dowelled that mistake and will have a fresh go at it later. I'm thinking about drilling a pilot hole in the middle of the screw with the dremel first, then getting the hand drill out and taking it real easy.

[pete.young]

[quote name='neepheid' post='204080' date='May 22 2008, 09:27 AM']Drilled out the two that were broken down in the hole somewhere, the drill had an existing hole to follow and drilled right into it and some metal filings later, I can fit the screw down the hole. Glue, dowel, mallet, wait, cut, sand, redrill.

Unfortunately, Peaty's prediction about the drill sliding came true with the one that was flush with the surface, but I've dowelled that mistake and will have a fresh go at it later. I'm thinking about drilling a pilot hole in the middle of the screw with the dremel first, then getting the hand drill out and taking it real easy.[/quote]

I'm wondering what a spark erosion machine is likely to do to wood. If it were metal stuck in metal, spark erosion is the way to go.

I'd be inclined to go at this with a pillar drill and a milling cutter, or use Peaty's suggestion.

I'm so glad you didn't use a screw extractor. They nearly always break, and then you are stuck with the problem of having an extremely hard broken-off stud extractor to get rid of.

[steve-soar]

Put the smallest router bit on your Dremel, and run it around the screw, then use needle nosed pliers to grab the exposed stump and carefully turn.
Adding some heat with a solder gun can expand the stump , so, creating a tiny bit of space around said stump, making it easier to rotate.

Edited May 22, 2008 by steve-soar