Drilling SS question.

[Anonymous7500]

Originally Posted by Wotname

Mate, I am sure you guys turn out very good work but the OP's work here isn't a major issue if he follows the general advice running through the entire thread.

The general advice running through the entire thread is to us oil, cobalt and pilot holes. In my opinion, these three pieces of advice are wrong.

The OP admits being a novice by asking the question. A novice resharpening a drill with a angle grinder is not going to yield a sharper drill. A resharpened drill will never perform as well as new.

A 3/8" American made drill is about $3. Yes, I would bring a bunch. Cobalt drills cost 3-5 times as much as a standard drill. They won't last any longer when used in a hand drill.

Starting with a pilot drill will make the hole location more difficult to maintain. Even if the hole was properly transferred and center punched, keeping the pilot drill on location is difficult in good conditions. It will be very difficult on a floating work piece. We avoid pilot drilling holes whenever possible. Even with heavy machine tools it is difficult to avoid chatter.

Delmarry has good advice and so do you, Wotname.

[Privleoplag]

Hoohaa, you have 4 holes to drill and now about a dozen different suggested ways to do it. Why not drill 'em each a different way and report back on your findings. My guess is, if you're "putting your shoulder" into it when you drill a pilot hole with an 1/8 bit that will leave you with a broken bit stuck in the hole and a lot more mess than you started with.. Water has never been a good lubricant in my book.. Hey, but try it.. Myself, I know what I'd do. Carbide bits, 1 pilot hole. Just get 'er done...

[Cotemar]

Carbide bits in a hand tool will break easily.
Carbide is the LAST resort to use only if the SS work hardens.

The OP is on a mooring and a drill press will not fit on the bow where he wants to drill.

A good battery hand drill will do the job.

I was in the OP's shoes doing the same thing last week. I feel the pain.
Had to drill 4 holes 3/8 dia. on my anchor roller

[s/v Jedi]

Originally Posted by delmarrey

A mag drill on SS or a boat other then steel?



I'm going to need my foul weather boots now, it's getting deep in here.

You know that old, old, and experienced machinist too?! No you don't, or he would have explained you how the electrical flux from the Lithium batteries will align the atoms and make the mag drill stick to stainless like nothing else. You will have to remove the batteries to get it off again!

[DeborahLee]

Since your over water don't use oil to cool the drill, get a bottle of liquid dish soap at the dollar store.

[Cheechako]

Yeah, that mag drill is going to be great located in the few square inches available on the SS bow roller!

[Wotname]

Originally Posted by Anonymous7500

The general advice running through the entire thread is to us oil, cobalt and pilot holes. In my opinion, these three pieces of advice are wrong.

On re-reading the entire thread, yes, I see what you mean; most are saying that. I agree that oil is not the best (even cutting type oils), lots of water is best here. I note that the OP is planning to use a cordless drill . And yes, HSS bits are fine except as someone noted, maybe the Cobalt will become necessary if the job work hardens due to poor technique - quite possible given the OP's novice rating.

I would still elect to go for a 1/8" or 3/16" pilot hole but either way isn't crucial. YMMV

The OP admits being a novice by asking the question. A novice resharpening a drill with a angle grinder is not going to yield a sharper drill. A resharpened drill will never perform as well as new.

True enough!

A 3/8" American made drill is about $3. Yes, I would bring a bunch. Cobalt drills cost 3-5 times as much as a standard drill. They won't last any longer when used in a hand drill.

Must buy my next bits in the USA; can't really comment on the Cobalt drills, never used enough of them to properly know their characteristics. Given the price point and the OP's novice rating, I might go your way, a new bit for each hole and a couple of spare ones for when they chip at breakthough . At least he will have plenty to practice his re-sharpening skills on after the job is done

Starting with a pilot drill will make the hole location more difficult to maintain. Even if the hole was properly transferred and center punched, keeping the pilot drill on location is difficult in good conditions. It will be very difficult on a floating work piece. We avoid pilot drilling holes whenever possible. Even with heavy machine tools it is difficult to avoid chatter.

At least he will be drilling vertically down! Should get someone in the dinghy to help sight from the side that he remains drilling at right angles to the job in both planes!
As for chatter might I humbly suggest that you try using a small cloth swatch as previously described in an earlier post. Most of my life I accepted chatter as unavoidable in some circumstances until I was shown this "trick". Never had chatter ever again - I know I sound like a broken record on this point but it is something so simple and so effective and almost most of us don't know about it.

Delmarry has good advice and so do you, Wotname.

Thanks and an interesting conversation (at least for me)

[Wotname]

Originally Posted by s/v Jedi

You know that old, old, and experienced machinist too?! No you don't, or he would have explained you how the electrical flux from the Lithium batteries will align the atoms and make the mag drill stick to stainless like nothing else. You will have to remove the batteries to get it off again!

WTF, why worry about the electrical flux - that is so yesterday. FFS, some of those old machinists need to get aboard the 21st century.

Geez Louise, everyone knows it's the magnetic-geo (ilumen) flux from the negative post of Li batteries that can be used to blast the holes (perfectly formed) into SS - only works on 304 (and partially on 316) - due of course to the particular nano-crevice crystalline structure of these materials.

Just take a the "hole maker" lead from the -ve post of a fully charge Li battery, dial the desired diameter into the battery monitor (it will work out the clearance requirements), place it on the marked point of the job, press the green go button and hey presto, one perfectly formed hole. No mess, no spatter, no heat, no swarf and no environmental damage. The removed metal travels back down the work lead and is converted back into a charge so that your Li battery remains fully charged for the next hole. We call it a win-win situation.

I note however that it not so good on Chinese sourced steel, possibly because the raw material comes from the southern hemisphere - perhaps if you reverse the lead end for end, it might help - not sure, never tried it,

YMMV.

[delmarrey]

Originally Posted by Privleoplag

Hoohaa, you have 4 holes to drill and now about a dozen different suggested ways to do it. Why not drill 'em each a different way and report back on your findings. My guess is, if you're "putting your shoulder" into it when you drill a pilot hole with an 1/8 bit that will leave you with a broken bit stuck in the hole and a lot more mess than you started with.. Water has never been a good lubricant in my book.. Hey, but try it.. Myself, I know what I'd do. Carbide bits, 1 pilot hole. Just get 'er done...

1/8" drills don't need much pressure if they are sharp.

As for water, it's not a lubricant. It's a coolant, which displaces heat, which eliminates the need for oil. Your not trying to lubricate a drill but reduce friction and keeps chips from sticking/welding to the tool/drill bit. When the friction overwhelms the process then you need water.

There are additives that can be put in the water which adds a bit of friction reduction but it's mostly to keep the parts from rusting. Oil is old school. Goto any machine shop and look at their high production machines. They are running coolant/water.

There are only two machines that use strictly oil that I can think of; a pipe threader and an EDM sinker.

Lathes, Mills, Planers, HBM's, CNC's and Drill Presses all use water/coolant. In my shop the only oil I use is when it's too much of a mess to clean up coolant for small jobs.

BTW I'm one of those old Machinists, I still have my square hole drill.

[Blue Crab]

When it gets this technical, you guys have to tell some of us when you're kidding.

[Wotname]

Post 53 is true enough, the rest is mainly BS

No.... wait...

[Anonymous7500]

Originally Posted by delmarrey

BTW I'm one of those old Machinists, I still have my square hole drill.

The square hole drill:

drill SQUARE HOLES Japanese form tool - YouTube

[delmarrey]

Originally Posted by Anonymous7500

The square hole drill:

That one's really heavy duty. Here's mine.

BTW notice, no oil.

.

[Cotemar]

Sweet square hole drill.
I used to be a machinist and have never had a need for that, but must be a need somewhere. We used to use a broach for square slots.

[bobconnie]

Square, hexagon, oval, anykind of drill ya want ! if your machinist enough to sharpen them !! LOL This old Machinist at 75 has sharpend them all and used them all ! And whenever I drill SS I use water and coolent. If ya don't want work hardend steel ya gotta keep it cool ! I would drill the holes in the SS in a drill press and the holes in the deck afterwards, with the Item as a guide ! But then I like things to fit and last !! Just sayin ya don't need to be a machinst to drill SS but good tools help !!