Now that the bus is in the driveway.
Need drill bits.
Going to drill every 6" and sparay low expansion foam in channell.
Will break and wear down bits. Need place to order quantity of same size.
I think that this has been discussed but I cannot find
thanks in advance
David
I like the Drill Doctor for re-sharpening bits.
Go to a commercial tool supplier and pay the man whatever he asks.
I once had to drill a lot of holes through 3/8" steel. The hardware store bits would last for 8 or 10 holes. I went to my friendly tool dealer and bought some that were 4 times the price, but they would do a hundred holes before even slowing down.
Brown Tool co
www.browntool.com (http://www.browntool.com) they are in OKC and sale to American Air Lines and others good drill bits at a good price
good luck
What are you drilling through and what size hole? What drill motor are you going to use?
Brian
I bought colbalt bits from McMaster-Carr when I drilled 1000 holes for riveting side planels. I think I got about 100 holes per bit.
Need to add type of bus to your info. I just did this to the 98 prevost. the thin tubing /mild steel isn't hard to drill and used one bit for entire coach. 3/16th 6 inch apart filled let expand till run out next upper hole then added more above etc. worth it? but can't see where it hurt. did same to bay doors. -they did not buldge! give time to expand before going to next level;I rushed it at first. 10 to 15 minutes. Hope this helps. Bob
I used cobalt, purchased at Grainger. One tool I purchased for the conversion was a Drill Doctor, paid for itself.
HTH JIm
I drilled over 3,000 holes for new rivets on my coach.
Bought a dozen good bits (tool supplier) and a drill doctor.
Only way to go!
Cliff
I take my drill bit to the bench grinder and sharpen it in under a minute. Takes a few tries to get it right, but you eventually get it.
JC
Thanks all. Will be buying good bits and a drill doctor.
Will a 18 volt rechargeable be too small? Do I need to use a corded drill motor?
If you are drilling stainless, you will be much happier with the cobalt bits.
definitely use a corded drill. Batteries won't last long at all.
Deb, you need a corded drill cordless drills kill a drill bit unless you buy the low speed bits and I don't know about the drill doctor I cannot make one work like JC I use the bench grinder and oil
good luck
I do not think you said what kind of material you are drilling. IMHO for aluminum you want to use a split point bit with a high speed(rpm) and low feed rate. For steel you want a slow speed(rpm) and high feed rate. Use some Boelube and the bits will last a long time. Try Travers tool online as a supplier.
Isn't the channel on a H series Prevost T1 or M4 steel ? drill bits come in all different angles so you may need to experiment a little with different bits you get the right angle on the bit for the type steel you are drilling a bit will last a long time
Fwiw most of the cheaper bits sharping doesn't do much good as the harden part is lost if they get hot
good luck
I actually had real good luck using cordless drills to drill my holes. I used a corded Dewalt drill some of the time, but it didn't work as well.
I was drilling into regular steel and found that high speeds worked the best. I thought steel should be drilled at low speed, but it took forever. I experimented with higher speeds and it drilled a lot faster and didn't seem to hurt the bits.
You are right about high speed as that seems to work better. I have a Milwaukee hole shooter that turns fast and had to drill some 1/2" holes under the bus and they went through very well . Jerry
Mild steel wants around 100 feet per second tool speed, using an plain HSS tool. For a 1/2" that is around 750 rpm. For a 3/8" hole, around 1,000 rpm. That assumes correct feed as well, and appropriate coolant. Half that is probably fine for a hand held drill. You need more pressure than a hand held drill can provide for the correct feed.
If I was drilling those holes, and I wanted clean round holes so I could plug them after, I would drill pilot holes with a 1/4" or a 3/16 drill, and use a Unibit step drill to bring it to size. I've got a couple of Unibits that I've had for 20 years and they still drill well in mild steel sheet. Only good up to around 16 gauge though, but they drill a round, smooth hole. A two flute drill tends to drill triangular three lobe holes in sheet steel.
Brian