Need advise on prevent splinterin & chipping

[ivan_aristizabal]

I heard that pre-coat with shellac will reduce splintering and chipping When V carving on some woods. Is it true? and what others variables (speed, rpms, type of cutter, wood type, depth of cut etc.) can help to get a clean carve. Any suggestions will be appreciated.
Ivan A.

[gergistheword]

I have used polyurethane on weathered barn boards to help keep the surface intact while carving. It worked very well. Be sure your bit is very sharp.

I'm guessing that shellac would perform about the same.

[Brady Watson]

I heard that pre-coat with shellac will reduce splintering and chipping When V carving on some woods. Is it true? and what others variables (speed, rpms, type of cutter, wood type, depth of cut etc.) can help to get a clean carve. Any suggestions will be appreciated.
Ivan A.

Crank the RPM up & slow the move speed down. Good quality tooling makes a difference - avoid bargain bits when it comes to V bits. Depending on size, lower your MS to 0.7,0.5 and see if that improves things. Every material is a little different, so play around. You want a light chipload without burning the material, and a slow speed to minimize vibration at the end of the cutter.


-B

[Bob Eustace]

Ivan the secret seems to be trying to use timber that V carves well and in particular without the dreaded fuzzies! Yes shellac helps a little but why cause yourself grief? Taking advice from this forum very early in the piece we took 15 pieces of different timber species and v carved the same file on each of them and hung them on the wall. You can then see at a glance what works well and we use it to convince customers not to request certain timbers. You do tend to forget how crook some timber is and this reminds you everyday if you hang it near the bot. Basically though we have found that hardwoods are best for V carving and modern good quality cutters as mentioned by Brady last for ages. Hope this helps.

[mikeacg]

Like Bob says! You can save a few bucks on a cheap piece of wood but then you'll spend hours ($$$) trying to sand it out and still never get something you will be happy with.

Mike

[Rob Gunn]

Ivan, You are not alone. I had a job just last week that caused me to pull my hair out. For the past 3 years we have been primarily cutting profile cuts in plywood to be used as sign blanks, a few large letters to be used on the signs, a few sign foam signs with names and addresses v-carved into them and all have been no issue. Last week I had a guy specifically ask for a "Cedar" sign with a simple text. Looked simple, just a some simple V-carved text, a little decorative scroll on each end, a pocket around the text and then finish with the outer profile cut. I have done dozens of these in sign foam with no issue so what would be the big deal in cedar? Well, after 3 scrap runs, and many tool path adjustments, I was finally able to get one done that was considered acceptable (but still had flaws). Lesson learned! I have no reason to ever want to do another job in cedar. Don't get me wrong, it can be done and I am sure there are guys out there that know all the tricks and would be happy to take that type of work. Then go for it, but take me off that list...

[Roy Harding]

I do a LOT of work on Northern Red Cedar (I make blanket chests and keepsake boxes). Cedar is my "schtick" - and I do a lot of vcarving on it.

The others have covered the main points - slow feed rate, high RPM, good tools. I also shellac the board before vcarving, then run the file, shellac AGAIN, and run the file AGAIN. This process works well, but is obviously not conducive to production runs.

All my work is custom, and my customers pay a premium for the time and effort involved - unless you're able to increase prices SIGNIFICANTLY for your work (and if you can, it can be worthwhile), I'd stay away from Cedar for vcarving.

[joe]

Rob,

Cedar is one of my favorites as you can see by my previous posts. However, I use rough cedar as my staple. The reason it carves so well is it's wet. Dry cedar will chip out no matter what.

I'm not saying this would work but it might be a good try to soak it down prior to carving.

The reason Cedar is so good as a sign material is it resistance to bugs and rot. Because the fibers are interlocking it stays together much like redwood. Another good softwood for V carving is yellow pine but it's so dense Vbits don't last long.

Another often used technique is re-surfacing with a belt sander or surface sander. You can get some really sharp edges that way.

[ivan_aristizabal]

Thanks to Greg, Brady, Bob, Michael, Rob, Roy & Joe, great feed back. I concluded that for clean V-carving go with hard-woods, use the sharpest cutters, eliminate vibration at the tip by tuning Feed & RPM. That applying shellac and making several passes could help as long time and cost are not an issue
Ivan A

[Roy Harding]

Well, Rob - now you have a few informed but dissenting opinions!!

Joe makes very good points which don't apply to my own situation.

You may want to experiment with the various suggestions made here to find a solution for your own situation.

Joe - I'll be making a cedar address sign for my house shortly - I've taken your comments on board and will give it a whirl!! (Green wood doesn't work for my normal work, as I'm carving joined products - chests and boxes - and need to work with dry wood so the joints don't disintegrate).