OP
OP
Acrylic sample from eBay arrived yesterday. Hand drill not used for 20 years, seized. Free off drill mechanism, but the jaws won't lock the drill bit! There's a part missing. Now have to spend an hour making a replacement part.
Performed half a dozen test operations successfully. It would appear that drilling to required size in one pass is the way to go. For a snug fit the bung requires a 4.6mm hole. Break-through is scary 
as the bit snags but thankfully the helix draws the swarf back out of the hole. The van's window now has one hole successfully drilled.
Now I'll have to wait for warmer weather to see if this is the solution to the between panes condensation problem.
Once again thanks for all of your help, suggestions and tips.
Does anyone know where I can find a supply of these bungs? (My local caravan/motorhome supplier tells me they're in short supply.
)
Performed half a dozen test operations successfully. It would appear that drilling to required size in one pass is the way to go. For a snug fit the bung requires a 4.6mm hole. Break-through is scary as the bit snags but thankfully the helix draws the swarf back out of the hole. The van's window now has one hole successfully drilled. Now I'll have to wait for warmer weather to see if this is the solution to the between panes condensation problem.Once again thanks for all of your help, suggestions and tips.
Does anyone know where I can find a supply of these bungs? (My local caravan/motorhome supplier tells me they're in short supply.
)
