Drilling holes in boiler banding.

[Michael CallaghanParticipant @michaelcallaghan68621]

Hi, today I had some fun trying to drill holes in thin strip brass for boiler banding. I only have larger vices and nothing small and gentle enough to to hold the band while drilling it.

There must be a way to hole the band in place to drill the holes without risk of bending or breaking the band.

What have you found the best method?

[noel shelleyParticipant @noelshelley55608]

Don’t ! Make a simple punch. Noel.

[PlasmaParticipant @plasma]

Hi, noel advised me to punch spring steel with a simple punch. It worked absolutely beautifully.

As I had quite a few to do and needed to be precise with the centering of each hole I modified a pneumatic hole punch off fleabay by making a new punch and die for it at the required hole size; 2.1mm

From silver steel I guess it took me a couple of hours to make and swap the tool set.

It cost me 30 quid and will come in handy again as it has a two sided head and can be used to make seams in steel sheet. 
<p style=”text-align: left;”></p>

[JasonBModerator @jasonb]

A finger plate is ideal for this, you can make a fancy one or do as I do and simply have a bit of flat stock with some tapped holes in it and use a screw and small clamp bar. A Vee ended clamp bar will be best for this as you can hold the strip either side of the hole. Even a piece of MDF, a wood screw and quickly knocked up clamp plate wil do.

Punching can often deform the soft brass not only the back of the hole but the width can bulge particularly if it is only 3mm wide like I tend to use mostly.

[PlasmaParticipant @plasma]

Jason is right, if the brass is thin it may well be deformed by punching. But it would be trial and error.

I made a finger plate using a hemingway kit and it is fantastic for small or thin items.

As Jason said, even a quick lash up would make your job much easier. Build one that will suit your drill press, I use a meddings high speed miniature drill for all my small stuff so there is plenty of room round the finger plate because the chuck is so small.

Mick.

[Nigel Graham 2Participant @nigelgraham2]

Also backing off the drill edges to give them a shallower, or nil, rake will reduce the chance of the brass grabbing and trying to climb the flutes.

Depending on the size you need, a small-diameter step-drill may be better than a twist-drill, though might not be available down to the diameter you need. (These are made for drilling sheet material.)

Drill into a suitable backing plate: e.g. some scrap plywood, MDF, off-cut of laminated chipboard.

 

[bernard towersParticipant @bernardtowers37738]

If you have to drill it sandwich it between two sacrificial pieces of material but punching is the way to go and the uncles that deform are 1 badly made 2 blunt and 3 not enough support .

[Paul LousickParticipant @paullousick59116]

Punches work well on thin metal but who has them in their home workshop?

Sandwich between 2 sacrificial pieces (as comment above) is a simple method.  The sacrificial pieces could also be used as a jig for drilling additional holes in the same position on other banding.

[bernard towers]

On bernard towers Said:

If you have to drill it sandwich it between two sacrificial pieces of material but punching is the way to go and the uncles that deform are 1 badly made 2 blunt and 3 not enough support .

This is the method that has always worked well for me.

[JasonBModerator @jasonb]

The forked end of the clamp is not far off sandwiching, you are clamping the work down flat to something and the fork is like a top plate and just leaves enough room for you to see your punch mark and fit the drill bit in position.

Yes  well made punch and close fitting die/plates won’t burr the work but comes down to whether you are the type that wants to get a project done or start another to complete the first. You would also need a way to position the strip in the die as you can’t see what you are doing.

Michael, what size strip and hole are you talking of? I typically use 3mm wide strip and 1.6mm holes, quite often drilling after bending.

[bernard towersParticipant @bernardtowers37738]

Sorry Jason but its not all about the end result sometimes its the journey.

[bernard towers]

On bernard towers Said:

Sorry Jason but its not all about the end result sometimes its the journey.

Yep, that is why I mentioned either option in my reply.

“you can make a fancy one or do as I do”

Upto the OP to decide which way they want to go. Be it a finger plate or punch – fancy or quick to get the job done.

[JasonBModerator @jasonb]

I suppose it may help if someone showed their “simple punch” as the OP may not know what is required as it is the die as much as the punch that is important and someone not knowing may make just a punch. I use to have a little one with various holes for plastic card when I made that sort of model.

[CirclipParticipant @circlip]

Yes Jason but we were knocking holes in metal with a hand punch long before playing with plastics. The name ‘Whitney’ springs to mind. Us long in the tooth ‘Wrinkly’ Ingineers will remember them.

Regards  Ian.

[David George 1Participant @davidgeorge1]

This is the punch set I made whilst I was an apprentice. The top plate guides the punch if just waking washers or shims and with with top plate removed I hold the punch in the drill chuck locate the hole clamp and then just put metal over hole and press out. It has a range of hole sizes. 1/8″ to 5/8″ I think. The most of punches are just hardend dowel pins with the end sharpened  with slight angle to cut easily.

 

[JasonBModerator @jasonb]

David, that is not unlike the one I had for plastic. Circlip, it also worked on lead foil and photo etch so not just new fangled plastic.

The one difference was the top plate was perspex or similar clear plastic so you could see where you were punching the hole. Ok if you just want a hole as the first part of making a washer or say buttons for a model figure but how would you easily place a hole central and 1.5mm in from the end of a 3mm wide strip on that one particularly if the material is thinner than the spacer between the top guide plate and bottom die plate?

This is the sort of thing I had, clear plate and the guide dowels are separate to the thumb screw threads so a closer alignment of top & bottom plate and it allow the plate to clamp the work and hold it in position while you make the hole. Not sure about the toffee hammer with that one.

[JasonBModerator @jasonb]

Well as I said this has got me to my destination of over 60 models, other routes are available depending on which way you prefer to get to your destination .

Bit of flat bar at the bottom in this case looks like 1.5″ x 1/4″. Tapped M6 for the nut and screw. Modified Unimat3 Clamp plate with thinned and notched end. A piece of 20 x 5 flat bar or whatever you have will do with a slot and hole at the end tapped for a M6 jacking screw at the far end

In use a bit of scrap is placed under the work (sometimes!) and the work clamped in place. The notch allows you to see your marking out and punch mark ( green dot for the photo) and allows room for the drill bit. The scrap at the bottom and the clamp plate effectively “sandwich” the work and the scrap helps stop the drill pulling into the work as it exits.

Hold it in the drill vice to give it a bit of weight and security.

Think it’s about time for a new bottom plate, as you can see it has had some use!

 

[Author]

Posts