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. 
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[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.

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