knots

[Charlie Knighton]

i have been turning some spalted southern red oak and the blanks have been aged in cardboard barrels

if the blank did not split i turned form, but some of the blanks had knots in them.

what can i do in the future to lessen cracking in the knots?, if i use ca glue spread over the knot it messes up the finish

i have one bowl which cracked very little (crack at 3 o'clock position) but warped a bit and one hf which the crack is larger and noticeable

the cracks appear a couple of days after the turnings is complete and the form is doing final drying i guess

all blanks came from the same tree

 

[hockenbery]

Charlie,

Knots usually crack or separate from the surrounding wood. the grain to f the knot runs sort of perpendicular to the grain surrounding it and shrinks in different directions as it dries.

CA glue can help if the piece is fairly thin.

two tricks to keep thin CA glue on the knot
1. coat the area surrounding the knot with Shellac the apply the CA glue. this usually masks the CA out of the area around the knot and sanding removes any trace of ca so it finishes nicely.
2. it it is a crack in the knot. Spray the surface with Accelerator then apply CA to the crack. The CA will wick into the crack and drie on the surface if it overflows the crack.

If i get a crack in a knot I usually trace the crack or its edges with a wood burner to blacken then and burn away the fussy fibers. this sort of highlight the knot.

happy turning,
Al

 

[Jim Keenan]

Charlie,

You might want to paint the area around the knots with Fiskit. A liquid masking product. I usually mask first with tape, leaving about a quarter inch gap around the knot, and then paint with a small art brush the open area (not the knot)with fiskit and onto the tape edge (to make the tape easier to remove). secure the knot with thin CA. After everything dries, use a rubber eraser to remove the fisket and the tape. viola! The area around the knot will accept finish normally.

Art and hobby store carry the fiskit.