Advice sought on ways to stop a chisel jamming in wood when using a machine morticer

[gray]

Advice sought on ways to stop a chisel jamming in wood when using a machine morticer

I am morticing a fair few holes in treated pine (to make farm gates) The wood is probably still a bit damp from the treatment.

However whilst doing the 1st cut (into wood that is all around the chisel), the chisel always jams solid in the wood. It does not matter how deep I cut and withdraw. It still jams, and I have to knock the wood off the chisel.

I cannot use the machines clamp, as the wood is too thick.

It mortices OK with the next cuts that are adjacent.

Has anyone any constructive tips that could help, or do I just have to grin and bear it.

[Bob Minchin]

Technically the work you are doing is too big for the machine but that is what happens in DIY all the time. Improvise some larger capacity holddown clamp for the workpiece.

Bob

[gray]

Out comes my heavy duty G clamps then. A bit time consuming, but if thats what it takes.

[Cash]

Gray,

Out of interest, do you have the auger 'sticking' slightly out of the end of 'chisel' to take most the waste away before the chisel 'slices' the sides?

Cash

[Dave Liquorice]

Tried rubbing some candle wax into the outside of the of the chisel?

[Harry Bloomfield]

gray formulated on Friday :

To help prevent a saw sticking in moist wood, you rub a candle down the sides of the saw. Might the same thing help with your chisel?

[The Medway Handyman]

?_dyncharset=UTF-8&fh_search=ptfe+sprayWorks a treat on saw blades.

[Thomas Prufer]

Can you drill a smaller hole with i.e. a spade bit to provide some clearance, and see if that helps?

Thomas Prufer

[Frank Erskine]

I'd have thought _you_ would recommend WD-40... :-)

[Andy Dingley]

Good chisels (these are sadly impossible to find in the popular small machine fittings)

Sharp augers (work on them with a diamond stone)

Most of all, accurate depth adjustment of chisel relative to auger. Use the "nickel trick".

Remove chisel and auger. Take a 5p piece. Place it under the shoulder of the chisel and fit the chisel to the machine, such that it's a little proud (downwards) of usual. Fit the auger, pushing it lightly into place against the chisel before tightening. Slacken the chisel, remove the 5p and push the chisel fully home before re-tightening.

You now have 5p thickness worth of clearance between chisel and auger, which is about right. Maybe increase it in green timber.

[Bob Minchin]

The wax will come off and stop the subsequent glue from sticking properly.

Bob