I need ideas.

[Detling]

I need to cut a 42 or 45mm hole through a 5 inch Victorian wooden beam and I only have access to one side. Augers only seem to go to 35mm and hole saws do not have a long enough shank. Any suggestions please.

[system 4-50]

How precise does the hole have to be?

[ditchcrawler]

Drill a pilot hole through the beam . Take a 42 45 mm hole saw and remove drill bit replacing with a 6" length of steel rod. use the hole saw to depth of saw. Use a chisel to remove plug and then drill again.  You will need the rod to replace the drill bit to get the depth through the beam

[BEngo]

What is the beam made of?  Oak that old will be really hard.

The ancients would have used a shell auger, but If you have some gauge plate it is not hard to make a flat drill bit of any desired diameter.  Turn it with a brace rather than a power tool.

N

[Bod]

Brace and bit.

1, 5/8th bit will give the size, if you can find one!

An expansive bit will also do the job driven by a carpenters brace.  DO NOT try to use an expansive bit in a power drill, it doesn't work.  Power ones are about, but very rare, I've never seen one that size even advertised.

 

Bod.

 

[Detling]

I think it is pine, but that old so it is hard, I have got a 10mm auger through but it is certainly harder than the banana wood you get from B & Q. 

Edited May 24, 2020 by Detling

[WotEver]

Diamond tipped SDS hole cutting core drill should do it.  They come up to about a foot long.  You'll have to pull the cutter out regularly to clear the chips though.

Edited May 24, 2020 by WotEver

[Detling]

Did wonder about that my neighbour is a plumber and I didn't want to wreck his kit.

 

[WotEver]

 

Or... one of these:

https://www.cablecraft.co.uk/45mm-morse-hole-saw

 

Plus arbour:

https://www.cablecraft.co.uk/7-16-inch-shank-arbor-to-suit-hole-saws-for-32-152mm

 

Plus arbour extension: 

https://www.cablecraft.co.uk/arbor-extension-for-hole-saw

[TheBiscuits]

Woodworm precision display team ... 

[Jen-in-Wellies]

One of these. If it works on gold it will probably work on wood. Of course you need the underground lair and the machine gun toting henchpersons too.

 

 

Edited May 24, 2020 by Jen-in-Wellies

[Detling]

Thanks for the solutions. The laser though may scorch the wood, look what happened to Windsor castle. As to finding a well behaved woodworm team the wood has been treated so they may have to commit suicide. Others will be pursued, I knew someone out there would have the answer.

[Opener]

1 hour ago, system 4-50 said:

How precise does the hole have to be?

What about stitch-drilling? Draw the circle that you want then drill a series of smallish holes around the circle. Join those smaller holes using, maybe, a chisel or gouge then tidy with a file, large diameter bit or whatever. OK methodology if the finish is not critical or if you have a finisher to hide the rough edges. I used it to go through a caravan roof.

Edited May 24, 2020 by Opener
Smelling mistook.

[Richard T]

Use a Forstner bit with an extension shaft https://www.axminstertools.com/axcaliber-long-series-tct-boring-bits-ax867825

[Detling]

My neighbours diamond core drill came up trumps, the smoke alarm got upset with the scorching though.

[WotEver]

18 hours ago, Detling said:

My neighbours diamond core drill came up trumps, the smoke alarm got upset with the scorching though.

Now what did I say about frequently clearing the chips...?