What would you recommend for filling cracks in bowls etc discovered towards the end of turning and the job is too nice to throw away and start again.
Use Cyanoacrylate Glue; Super Glue; Hot Stuff; StarBond. these are USA terms, yours might be a bit different.
Actually, it's all the same chemistry with slight differences from one manufacturer to the other. Some formulations have viscosity differences, some slightly different prices.
Thin cracks, thin glue. Wide cracks, thick glue.
Zap with the commercial catalyst or a solution of baking soda in water. It cures anaerobic, so the zapper is whatever can blanket out the oxygen.
There are many things that do the job. Just a few ideas that come to mind.
- Try and pick up some brass, copper or other fine metal filings. Fill the crack with this and saturate with thin CA. Finish turn and sand as usual.
- Mix up some epoxy, add a colourent that compliments your turning and finish as usual.
- Fill the crack with sanding dust, either same wood or contrasting, and saturate with CA.
Depending on the size of the crack, different approaches can be used:
- If the crack is a hairline crack, thin CA glue will penetrate the crack all the way.
- For a slightly wider crack, thicker CA glue can be used.
- If the crack is a little wide, I often pack the crack with sanding or turning dust from the work piece (hoping for somewhat of a color match). Once packed, you can soak the dust with thin CA glue.
- For larger cracks, I use two-part epoxy with tint in it. I have used black and red, so far to good effect. The color makes the crack an interesting feature instead of an ugly defect.
I use masking tape to dam the cracks as necessary to prevent filler from running out.
If the crack penetrates all the way through the wood, you can dam the back side with masking tape and peel or turn away after it is dry. These techniques may require a few repeated applications to fully fill the void. Also, epoxy tends to get air bubbles which take several minutes to work to the surface and require refilling when dry.