Countersink shavings cutting skin...

danielhv · #1 10-31-2008, 08:16 PM

Problem after problem. Im CS the bottom skins on the fuel tank (above the rear baffle)... these are for 426-3-3.5's... so we're not talking that big here. But it seems on every 5 or 6 holes I have one that looks like this...

It appears the shavings are staying in the cage and cutting the skins... The only way I seem to be able to prevent this is to CS for half a second, remove shavings, repeat until proper depth... What am I doing wrong here? I have tried using boelube with no luck. I am CSing with a cordless drill, so im not spinning it very fast... Im using the #40 bit that came with my Planetools RV toolkit. And Im using a cage that has the white nylon boot at the end to protect the skin...

Next question, How do I fix the ones that already look like this??

And I know some are going to say "Go get a no-hole bit", but I dont think these should be doing THIS!

Don Jones · #2 10-31-2008, 08:22 PM

That looks awful deep to be done by the shavings. I just did these, no lube, cordless drill on fast speed, no problems!

danielhv · #3 10-31-2008, 08:27 PM

Dunno what else it would be?? The picture is making it look worse than it appears to the eye... That was taken with the lense less than 2 inches from the hole.

Mel · #4 10-31-2008, 08:38 PM

Daniel,
You may be using too much pressure causing the chips to be too large. Try running a little faster speed and less pressure.

szicree · #5 10-31-2008, 08:38 PM

That countersink with the hole loves to do that. Get a no-hole c.s. and the problem will go away.

danielhv · #6 10-31-2008, 08:44 PM

Quote:

Originally Posted by Mel

Daniel,
You may be using too much pressure causing the chips to be too large. Try running a little faster speed and less pressure.

Ill give that a shot... how do u suggest I fix the ones that are there?

Mel · #7 10-31-2008, 08:45 PM

I wouldn't worry about them. A little scotch-brite will take care of them.

danielhv · #8 10-31-2008, 08:59 PM

Quote:

Originally Posted by Mel

I wouldn't worry about them. A little scotch-brite will take care of them.

Thank you sir!

alpinelakespilot2000 · #9 10-31-2008, 11:34 PM

Quote:

Originally Posted by danielhv

And I know some are going to say "Go get a no-hole bit", but I dont think these should be doing THIS!

Yes, this is what you really need to do. You've found the one drawback of the single-hole cutter. I have a couple halos on my tanks as well. I would countersink in at least two or more passes, increasing the depth on the second and third pass. That should address the problems if you don't want to spend $5-10 on a 3-flute cutter.

BrentHumphreys · #10 11-01-2008, 07:12 AM

Could somebody show me the difference between a hole and no-hole countersink?

Are we talking about the flutes?