Help with chipping while carving cedar

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hey guys

I’ve been making some cedar signs lately and i’m having a problem with some chipping while carving. I’m using a 1/8" upcut bit to do the roughing pass, and a 1/16" upcut to do the detail pass. and some of the smaller details are chipping out. I’ve been cutting down cedar into 1 1/2" x 1 1/2" strips then edge gluing them to the size I need. was wondering if there was anything i could apply before hand that would help. I plan on painting the pocket letters and staining the rest of the sign so if I was going to apply something beforehand it would have to be able to take stain afterwards.

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Switch to a downcut bit. You can also surface finish your stock to lock those wood fibers together a bit.

An upcut bit is going to blow it out.

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what do you mean surface finish? I will definitely be getting some other bits, but as this is for a customer and I have a deadline I will have to work with what I have.

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its a soft wood best you can do is slow it to half the ipm and hope it does not snag any grain that is usually how blow out happens to me.

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You can’t change this in Easel, but when working with Fusion 360 recently on a piece carved in cedar I found that carving with a climb cut (rather than conventional) seemed to greatly reduce the chipping.

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Try putting a couple light coats of spray shellac on the wood before you machine it. That helps a bit. Also, what are your cut settings, DOC and feedrate?

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A light coat of sanding sealer, shellac, hardener etc.

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Running the machine at 45 ipm and .05 doc

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you might try to run a couple of passes at .01 or .02 just to break the surface grain with less stress. Stop it, and then restart with regular settings.

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would it be better to do the detail pass first or the roughing pass first?

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for basic letters, you should be able to get away without doing a roughing pass.

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I agree with @JDM about making a couple shallow passes first. You may also want to reduce your overall depth of cut from .050" to .035" or so.

I don’t know how deep you’re cutting the letters, but my first engraving cuts were as deep as 1/2". My most recent was only 1/8", and it looks better than the deep cuts. It also reduced the cut time dramatically, and was easier to paint in the pockets. You may consider making a sample sign with cut depths from .025" to .250" to show off the difference with shadows and viewing angles. If you can convince your customers to accept a shallower cut, you’ll be ahead on time and bit wear.

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So I got my second piece of edge glued cedar all ready, and this time I applied a coat of sanding sealer before carving which so far has helped immensely. I also ran the first pass at .01" my final pocket will be .17" deep and I was running at .04" per pass. ( I know the final pass is only carving .01") I have not run the detail pass yet, we will see tomorrow how well the sanding sealer helped.

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