The Project Has Begun: Harman Mark III Heating Coil Install

Got some time off from work & started my coil project. Spent most of yesterday & this morning planning & shopping for supplies. I have all my pipe, fittings, solder, etc. & I'm ready to rock!

Got started on drilling thru the stove for the coil. I knew this wouldn't be easy, or fun. I've got one hole down with 3 to go, & my hole-saw is SMOKED! Off to the hardware store I go, ONCE AGAIN!

I will have this done come hell or high water by Saturday night at the latest. I will keep posting my progress for anyone else who is thinking about doing this. Enjoy the pics........

Smitty, I drilled two 3/4" through my SF250. Not too hard. I used a 3/4" bit and ran 3/4"od tube. But the bit wasn't cheap and may need to be sharpened if I were to use it again.

Does anyone here have any tips in drill bit sharping?

This is a 1 1/8" hole saw -- it came with the coils ( for an additional charge, of course).

There are desktop drill bit sharpeners out there.I think sears might even have one, but not sure how good it is. I need one bad -- I go thru bits like crazy working on cars & bikes

Smitty I tryed useing a cordless dewalt when I did mine but it just didn't have the torque to get the job done. I got the 1/2 corded drill slower speed and good cutting oil I had two 1 1/8 hole done in 25 mint.

Hey Smitty,

Drilling through thick metal isn't an easy job. The hole saws don't stand up to thick steel, as you know. I use 3 or 4 bits, starting with a small one and getting larger until I have the size I need. The enemy of the edge on a drill bit is heat. As Razzler said slower speed is better, and lots of cutting oil. A variable speed corded drill works best, more torque at slow speeds.

I have 2 Craftsman drill sharpening jigs, old ones that mount on a horizontal surface and use the side of the grinding wheel. I can sharpen almost any drill bit except the Cobalt bits and ones like that. Once they loose their edge they can be resharpened but won't stand up to any heavy work.

Once those holes are done you can start to enjoy the project.

Just got back from store -- $51 later They only had 3 Dewalt 1 1/8 in saws, so I bought them all, then had to buy the stupid arbor that goes with that type....

Yeah, I just learned the hard way to be patient & GO SLOOOOOOW! I've been dumping WD-40 on both bits -- even the one that broke.

I just finished the second hole & the bit is perfect -- I kept the speed slow & put less pressure on, & just let the bit cut. Now, if I had done that to begin with......

2 more to go! :box:

Smitty use cutting oil (Wd-40 won't work and may make things worse, even 30 weight motor oil would be better )slow speed and let the hole saw do the work . I wish I got here sooner get milwakee bimetal ice hardened hole saws they are the best other than hougen cutters which are $$$. The milwakee's will hold up to 316L stailess which is just about as hard as tooling steel. If you had time order some accu-lube stick lubricant from thhe Do-All company. A stick costs $3 plus shipping a little goes a long way and makes drill bits and holessaws last a long time.

Cap drill bit sharpening by hand is still the best. As John said they make some fixtures but a skillfull fabricator can sharpen one even better free hand. The best tool to use is a bench grinder with a 60 grit wheel on it. Try and imitate the factory bevel and shape using the normal grinding edge not the side which can cause normal wheels to fly apart. I'll have to get richard to help me get vidio of drill sharpening on here.

SMITTY wrote:I've been dumping WD-40 on both bits

If you can get cutting oil it works allot better then penetrating oil, I don't now why it does but it makes a BIG difference.

shape using the normal grinding edge not the side which can cause normal wheels to fly apart.

Exactly right. The wheel is not made for grinding on the sides, but that is how the sharpening jigs I have work. When sharpening a bit this way you only take small amounts off at a time.

OK -- now I'm making progress! It's amazing what some quality drill bits will do......

Razzler wrote:If you can get cutting oil it works allot better then penetrating oil, I don't now why it does but it makes a BIG difference.

jpen1 wrote:get milwakee bimetal ice hardened hole saws they are the best

Thanks for the tips, guys!

I'm the most impatient person on the planet -- so I don't want to drive any farther than the local hardware store (limited selection) because I'll get severe road-rage , & I can't wait for an order -- it'll take too long. I'll definitely buy some cutting oil for the next job, whatever that may be & keep the Milwaukee saws in mind -- I used to use their sawzall & blades when I did industrial roofing over a decade ago. Stuff was tough as nails. I could cut through corrugated decking for hours on the same blade! And the sawsall took more than a few flights off the roof after so many bad days. Still had the same one for over 4 years.

I only have 1 more to do, so I gotta dance with what brung me.

Smitty

What coils did you get, are you going to use two?

Chris

Congrats on getting three done...now for number four! You go guy!

I prefer Lenox hole saws over Milwaukie. As a matter of fact I prefer Lenox anything over Milwaukie anything. Lenox has it figured out. Their metal cutting bandsaw blades outlast Milwaukie big time.

They had Lennox saws there but they only had a 1-1/2" & not the 1-1/8". I bought their arbor & drill bit though -- that parts holding up great too!

franknbaum wrote:Smitty

What coils did you get, are you going to use two?

Chris

Yes I am using 2 in series ( I want the oil burner OFF this year! ). I bought them from Hilkoil: http://www.hilkoil.com/product.htm#table

Got the biggest ones they make -- the 21T -- there is just over 6 feet of pipe in each coil ! Cost a bit of $$$, especially for shipping ( like $40 ) but they got here in 1 day, & should pay for themselves after just one season.

Moving right along here.........

Now, time to plumb!