Help with chipping while carving cedar

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.

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.

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.

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.

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.

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?

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

Running the machine at 45 ipm and .05 doc

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.

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

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

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.

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.