Hole punching into alloy

[crankedup]

I've asked in bodywork section but repeat here as I know a few guys do bodywork. I need to punch/drill out 2x 45mm holes in the sheet alloy that forms the scuttle on my car. The scuttle is not flat. I have seen the hole punch sets in Frost cat' but has anyone any experiences of this type of work/product? Obviously I needto be wary of distorting the alloy surrounding the holes.

[tr7v8]

2 ways of doing it a "Q Max" punch which is a punch you wind up with an allen key. Good tend to be very expensive especially if only a couple of holes to do although copies are around which are cheaper.
The other option is some form of hole saws which look like either a circular hacksaw blade, this is probably the best bet. Or another trepanning type tool like dividers that go in a drill. These are cheaper but can be swines to use especially in a confined space or in thick metal. They grab & skip but are generally OK if you take it slowly.

[austin]

Or mark it out and chain drill and finish with a file. Would probably put less stress on the metal than trying to use a punch or hole saw.

I guess this is for your Swallow vents...

[DickyC]

austin said:

Or mark it out and chain drill and finish with a file. Would probably put less stress on the metal than trying to use a punch or hole saw.

I guess this is for your Swallow vents...

Agreed. And if you do go for chain drilling, wodge up a load of masking tape sticky side out and stick it firmly behind where you're drilling and filing to catch the swarf.

[crankedup]

Thank you for good advise guys, I have opted to go the Q Max route and ordered the 45mm item I require.
Yes Austin this is for my 'Swallow' scuttle vents fitting, hope to fit them by this weekend.

[Compo_Simmonite]

I've got a selection of QMax punches and rate them highly so they are my recommend method

Paul H.

[anonymous-user]

cut 12 holes in the bonnet of my mates Locost with a hole saw (48mm) bought a good quality saw, (the blade was only adout 7mm deep so only good for sheet), clamped the bonnet to a piece of scrap wood, real good job,

[crankedup]

I have the size Q Max bit that I need in the post now, as the scuttle is fixed in place on my car it seems the easiest way forward to fix the scuttle vents for me. Thanks for all comments.

[tr7v8]

crankedup said:

I have the size Q Max bit that I need in the post now, as the scuttle is fixed in place on my car it seems the easiest way forward to fix the scuttle vents for me. Thanks for all comments.

Grease the thread on the bolt & the two halves of the punch, it'll go through with less effort.

[crankedup]

tr7v8 said:

crankedup said:

I have the size Q Max bit that I need in the post now, as the scuttle is fixed in place on my car it seems the easiest way forward to fix the scuttle vents for me. Thanks for all comments.

Grease the thread on the bolt & the two halves of the punch, it'll go through with less effort.

Will do, thanks for tip.