Bob Corb Posted April 15, 2003 Share Posted April 15, 2003 I'm trying to fit a Watts Link kit but the rear bosses are full of powdercoat. I've slowly worked my way into the nearside boss using a tap and lots of lubrication, got a bit too keen on the offside and pushed too far without cleaning out the tap. Its sheared off in the boss leaving nothing sticking out - now I know how strong taps are(n't). It appears about 10mm is stuck in there. I dont suppose anyone can think of any way of boring out the old tap? I'm thinking of either drilling it with a carbide drill and then hitting it with a tapered centre punch to shatter it or just whacking it with a small cold chisel and punching out the remains (theres space behind to push it all out). If the thread gets damaged there's space to fit a big nut on the back of the boss. Feeling really stupid - if all else fails there will be a nice Watts Link kit for sale soon. ☹️ ☹️ ☹️ BC Link to comment Share on other sites More sharing options...
Luke Beaumont Posted April 15, 2003 Share Posted April 15, 2003 A quick google confirms my memory of the existence of tap extractors. They don't look particularly sturdy, but may just do the job. Maybe J&L sell them? Link to comment Share on other sites More sharing options...
I reply to every thread Posted April 16, 2003 Share Posted April 16, 2003 OooH - that's nasty ☹️ Makes me feel slightly better about my sheared cam cover spacer though. Good luck getting it out Link to comment Share on other sites More sharing options...
Bob Corb Posted April 16, 2003 Author Share Posted April 16, 2003 Luke - thanks for the tip, I've got an extractor on order from cromwell tools - £20 but will be money well spent (almost) if it works. Other option suggested by the welder here at CT was to weld a bolt to the end of the tap and wind it out, I'll try that second. He says he's recovered the remains of 5mm taps buried up to 15mm! He's well practiced.. Aparently there are machines at Cosworth Racing that do this all the time, now we're a separated from Racing he hasn't had to done one in a while but shouldn't be a problem. Bob Link to comment Share on other sites More sharing options...
wag Posted April 16, 2003 Share Posted April 16, 2003 Yes, tap extractor has 3 extending 'flukes' that engage in the flutes of the tap so you can wind it out. No chance of drilling it, its too hard. I bet you need to be skilled to work the welding trick. Link to comment Share on other sites More sharing options...
John Howe Posted April 16, 2003 Share Posted April 16, 2003 I'd go with the welding route as its quick... If the break is flush with the surface, dont weld a bolt to it but rather a nut. You can then weld through the centre of the nut and still have the flats to put a spanner on. JH Deliveries by Saffron, the yellow 222bhp Sausage delivery machine Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 16, 2003 Share Posted April 16, 2003 Bob. You have my sympathy. Dreadful. You won't drill it out as already stated, but some of the other ideas might work Good Luck Link to comment Share on other sites More sharing options...
sjwb Posted April 17, 2003 Share Posted April 17, 2003 'Spark Errosion' That's the way. Find a local machine shop / engine refurbishing establishment. Steve B Link to comment Share on other sites More sharing options...
Asklepios Posted April 17, 2003 Share Posted April 17, 2003 Yes --spark erosion is best,and in many cases only way. Link to comment Share on other sites More sharing options...
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