danielhv

danielhv

Well Known Member
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...

IMG_2901.JPG


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!
 
Can't imagine shavings doing that!

That looks awful deep to be done by the shavings. I just did these, no lube, cordless drill on fast speed, no problems!
 
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.
 
Daniel,
You may be using too much pressure causing the chips to be too large. Try running a little faster speed and less pressure.
 
That countersink with the hole loves to do that. Get a no-hole c.s. and the problem will go away.
 
Mel said:
Daniel,
You may be using too much pressure causing the chips to be too large. Try running a little faster speed and less pressure.
Click to expand...

Ill give that a shot... how do u suggest I fix the ones that are there?
 
I wouldn't worry about them. A little scotch-brite will take care of them.
 
danielhv said:
And I know some are going to say "Go get a no-hole bit", but I dont think these should be doing THIS!
Click to expand...
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.
 
I had similar results using that cutter, and quickly gave up on it. I got the 3-flute C/S bits and use a air die grinder to turn them at a high speed, using light pressure, and I get beautiful countersinks. It also turns the aluminum shavings into the finest confetti you've ever seen, extremely thin and incapable of dragging/cutting anything.
 
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