drilling out spot welds

[BIGS]

Is it 8mm drill size i need to drill out spot welds? Im asking for the proper tool but people dont seem to have a clue.

[brainsnova]

i ve only seen a drill bit or grinder used.

[L14MNP]

Get the proper drill bit mate (flat end) I have a couple from Machine Mart (6 quid) but they are the crap ones with a sprung point which you are supposed to locate over the weld after you centre punch it. Can be annoying if it skips about.
At least you know they are available there if you can't find a proper one.

[craig green]

Proper spot weld drill-bit FTW.

You just make a mess otherwise.

[BIGS]

you mean like this one?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=290280716970

So leave the one from Machine Mart then

[L14MNP]

Aye dude the one in your link is the one. Machine Mart ones suck and make you swear lol

[BIGS]

Ah right ill take that one back then lol. ill buy the one in the link. just mean i wont get the car done till after christmas :(

[ck]

use a spot weld drill like i use. sprung pin in he middle and a reversible cutter. it cuts through 1 panel and not all the way through. so much tidier ect.

like this
http://cgi.ebay.co.uk/Facom-Sykes-Zipcut-Spot-Weld-Remover-Cutter-Drill_W0QQitemZ310102368658QQcmdZViewItemQQptZUK_M easuring_Tools_Levels?hash=item310102368658&_trksid=p3286.c0.m14&_trkparms=72%3A1301%7C66%3A4%7C65%3A12%7C39%3A1%7C 240%3A1318

[burgo]

i dont get why that would only go through one panel?

[L14MNP]

They do if you go easy lol

[burgo]

but the "proper" ones only go through one panel if you go carefully.

[L14MNP]

Yeah. The ones without the sprung pin are far superior IMO. Go slow and nowts a bother.

[BIGS]

Well ive just gone out and bought one. cost me £9.50 but atleast ive got it here. Thanks for all the help everyone

[Mike]

You can make a spot weld drill using a normal 8mm HSS bit and a grinder.

[Andy]

I used normal bits as i lost my spot weld bit,was no different

[The Simps]

I've tried both types of drill bit but have found grinder to be far easier, quicker and a neater job. Drilling them out its too easy to go right through on thin panels or miss the weld and only get half of it. Will cost you more in discs with the grinder tho.

[meritlover]

the ones we use are a better design. its like a 7 or 8mm hole saw with a sprung centre point. the 'saws' are reversible and replaceable cheaper than a drill bit and leave a better surface to work with after.

[Pistol Pete]

I think i used 8mm spot weld drill bits when i did mine. Bought a few and went to town on it lol

[meritlover]

the ones we use are a better design. its like a 7 or 8mm hole saw with a sprung centre point. the 'saws' are reversible and replaceable cheaper than a drill bit and leave a better surface to work with after.

http://cgi.ebay.co.uk/Facom-Sykes-Zipcut-Spot-Weld-Remover-Cutter-Drill_W0QQitemZ310102368658QQcmdZViewItemQQptZUK_M easuring_Tools_Levels?hash=item310102368658&_trksid=p3286.c0.m14&_trkparms=72%3A1299%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318

[Pistol Pete]

I used these type with no problems:

http://cgi.ebay.co.uk/spot-weld-drill-bits_W0QQitemZ170286153962QQcmdZViewItemQQptZUK_Ho me_Garden_PowerTools_SM?hash=item170286153962&_trksid=p3286.c0.m14&_trkparms=72%3A1301%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318

[L14MNP]

the ones we use are a better design. its like a 7 or 8mm hole saw with a sprung centre point. the 'saws' are reversible and replaceable cheaper than a drill bit and leave a better surface to work with after.

Theses have already been dicussed overleaf my friend :(

[meritlover]

and i agree whole heartedly

[L14MNP]

Excellent. A mechanical discussion on PNG that ends with all involved still very good friends :) x

[Stuart]

you could go balls out and get a mag drill, 8mm flat drill bit and set the depth to the pannel thickness :D but thats a very expensive route lol.

I swear I've seen an air drill that has a flat bit and depth stop on it to do a simlar job... again pricey, but I bet it gets the job done in a fraction of the time

[BIGS]

Hmm well the bit ive bought is a good drill bit going through like the metal is jelly lol. But because it is so rusty at the front i cant see where i have to drill next. well ill be making a thread in a mo so if anyone could help me on it would be great

[meritlover]

wire bush the rust and try and lever the skins apart to expose where the spot welds are, then centre dab them before drilling. once you start you soon see where they are. and if its still on tight.....then you must have missed some.

[Steve]

Another good thread, ive just bought the drill bit with the centre bit but the other ones look better. Well I suppose either will be better than using regular 8mm drill bits like ive been! lol

[L14MNP]

Just been using mine today. The flat type not the hole cutter. Absoloutley files through them and I've maybe torn 3 out of about 25

[Steve]

How long did they last before they went blunt? I gave up using regular drill bits as they gave up after going through a few welds lol

[L14MNP]

Never tried with regulars lol I used to just hammer and chisel/tear the panels off :( Been through a good 100 with this 6/7 quid Screwfix job and it's still razor sharp. You don't even need to centre punch them. :)

The sprung hole cutter types were dying on me after maybe 20-30, even when brand new I found they skipped about and were terrible on anything but a 100% flat panel despite using a centre punch!

[Steve]

With the regualrs I was doing it the other way around - drilling them mostly out then chisseling the rest off. Just ordered one of THESE (http://cgi.ebay.co.uk/DORMER-8mm-COBALT-SPOT-WELD-DRILLS_W0QQitemZ290303775503QQcmdZViewItemQQptZUK_ Body_Shop_Supplies_Paint?hash=item290303775503&_trksid=p3286.c0.m14&_trkparms=72%3A1683%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318) So hopefully this will do the trick.

[L14MNP]

That's a good price! Free p&p FTW.

You won't be dissapointed mate.

[Steve]

Well got mine the other day and at first it was going through them really easy but after only drilling out about 10 - 15 spot welds it seems to have almost given up!? wtf? Having to apply loads of pressure now and they're not even getting through.

Would have thought they would last a bit longer than that?!

[Pistol Pete]

Let the drill do the work. The edges will burn off with too much pressure. I used 2 drills getting off my front panel and lower cross member.

[Steve]

Thats just it though - at first I hardly had to apply any pressure and they drilled out easily. Now im having to apply alot of pressure just to make a mark on the welds..

[Pistol Pete]

Tips will wear out with heat. Keep at it.

[Steve]

Ok well can't be bothered going back out to the garage today, will give another go tomorrow and probably order another couple just in case.

[jord4n]

i have done this with the same drill but you have, i found using a veruble drill helps. just go slow its not a race. the reson your drill bit has worn out is you have gone to fast heated it up to much and recked it.

i did the whole front panel and upper crossmember with only one drill bit with a dewalt 18v cordless, plug in ones are usless for thsi type of drilling.

jord

[Steve]

Cheers, might give the cordless a go but they take ages to charge up. Failing that i'll just take my time with the electric drill.