Drilling through stainless steel

[Phonse]

Good question - lots of good answers. Alternatively, don't drill. See aproposmarine.com for no-drill treads.

[Silverbullet]

I attached mine with epoxy resin and fiberglass matte. Wrapped the rungs with saturated matte. When it hardened I sanded any glass fibers sticking out. Then I applied saturated matte almost out to the edges of the wood. Then applied the saturated matte to the wood. Sanded off any glass fibers. Rounded the wood, tidewater cypress, with the router but you can do it with a sander. It will be there till the cows come home. No drilling! You need to stuff some saturated matte under the wood in contact with the rungs to add strength.

[Rotten Ricky]

Please excuse being slightly off topic, but as an important (often unknown!) safety issue, make sure your ladder extends at least 3 ft into the water. It is otherwise near impossible to get your feet onto the bottom rung of one that is only a foot or so deep, and unless your arms have the strength of Hercules and unless you are not exhausted from being in the water, a short ladder will be useless. This is from my own experience - try it yourself!



Best thing is to buy a second simple ladder and have it fold out from between the last two rungs. Make sure the second ladder is slightly narrower than the first, so it just needs one bolt creating a hinge on each side to connect the vertical pieces. The second ladder is prevented from opening into a vertical straight line by the bottom rung of the first ladder, making it easier to climb onto when it sticks out from the transom. Works very well and folds up "inside" the first ladder when stored. Makes an enormous difference for rescue!



Cheers, Rotten Ricky.

[Cadence]

Originally Posted by Phonse

Good question - lots of good answers. Alternatively, don't drill. See aproposmarine.com for no-drill treads.

Amen!

[sailorladd]

Drilling stainless steel can be very challenging, especially without a drill press.... It also makes a difference what type of stainless is being drilled... The finest grade stainless steel is 316L which is medical grade and is used a lot on boat fittings, but now and then 304 is used which is cheaper and has more carbon in it and is quite a lot harder than the 316L which is more pure.

The way I would approach drilling in the field (without a drill press) is using a slow speed drill (a battery drill works just fine) and I would center punch where I wanted the hole, as the bit will wander around most annoyingly... I would have a cooling/cutting oil handy to keep the spot cool, and help with cutting, in a pinch one could use kerosene or even paint thinners, just have a little paint brush handy and dab on a quantity intermittently as you drill, and what I do is hold the drill level and use a good firm pressure on top, pressing down on your work and drill in a series of stops and starts, don't keep the drill running all the time, this way you keep the steel from heating up, and it enables you to press down firmly and evenly (like a drill press)

What I would consider doing if drilling a sizeable hole is to drill a smallish pilot hole first, and then the right and final size, just a snug fit without too much play... Good luck and wear safety glasses.

[Rotten Ricky]

Originally Posted by Silverbullet

I attached mine with epoxy resin and fiberglass matte. Wrapped the rungs with saturated matte. When it hardened I sanded any glass fibers sticking out. Then I applied saturated matte almost out to the edges of the wood. Then applied the saturated matte to the wood. Sanded off any glass fibers. Rounded the wood, tidewater cypress, with the router but you can do it with a sander. It will be there till the cows come home. No drilling! You need to stuff some saturated matte under the wood in contact with the rungs to add strength.

Unless your glass and/or wood rungs extended all the way out to the vertical members of the ladder, or you created some holes or roughness or some kind of indentation (such as by a hammer) in the s/s rungs, I think it highly likely that with the heating and cooling of dissimilar materials, your wooden rungs will started rotating around the pipe rungs before long. Even with epoxy... Sorry about that...!



Cheers, Rotten Ricky.

[Terra Nova]

Originally Posted by sailorladd

...drill in a series of stops and starts, don't keep the drill running all the time...

Do NOT follow this advice!

Once the drill bit starts cutting keep it cutting until the hole is through. Stopping and restarting work hardens the stainless.

[Cadence]

A bunch of good advice about drilling stainless. The OP should consider steps that clap on. Maybe requiring a center punch divit, for a set screw.

[nichollsjr]

Originally Posted by Bigjim

My transom swim ladder is made of hardy stainless steel tubing. It does not have wooden steps or rungs. So, it is difficult to climb out of the water.



I purchased some teak steps but when I tried drilling the holes for the machine screws the steel burned out two drill bits, a normal steel bit and a cobalt bit. I then bought a titanium one but it fared no better.

Anyone have a suggestion on what type of bit will work with this sturdy tubing?

My suggestion is..don't drill holes. I have fitted steps on several ladders by using straps. With a hole saw, cut half circles at the end of the step exactly the inside dimension between the vertical pieces so that the step will set ontop of the ladder rung with "ears" on both sides of the vertical section. Then either strap the step from the underside or connect the ears together at both ends of the step, flush with the vertical portion.

[abnt1]

Hi, I second the suggestion of carbide bits, also use a dipping cup filled with cutting fluid to cool the bit as you go.

[Cadence]

Someone suggested it. Take some teak pieces longer than the distance between the tubes. Drill holes the diameter of the tubes, on tube centers, cut them laterally at the holes. Place them on top of the existing steps and through screw the tails to form clamps. radius ends finish as desired. Possibly route some grooves on the steps radius all edges.. Probably one hell of a lot better than drilling and weakening the ladder.

[PirateBarnabus]

Cobalt drills and very slow speed plus coolant to avoid excess heat.
That's what I use although I'm going to try carbide if I can find it based on the above comment.

Cheap drills are a complete waste of time in my view.

[djblizzard]

Try to drill with a very slow speed of the bit, when it begins to bite, keep the speed slow. The drill bit will fall if it heats up too much, so use a lubricant. A light oil works well.
Beware the last few turns as the bit will shatter...

[JasonL]

Here is a very wise old man hint!
Mold a little Plasticene/Childrens clay, or, household window sealing putty, around the spot to be drilled, fill that with your chouce of cutting fluid.

[jambrw]

Sharp dril bit slow rpm and don't stop