Milling Mahogany

[Byron Trantham]

I have been milling - routing mahogany for the last couple weeks and have encountered a problem I can't seem to deal with. The grain will "tear out" here and there. When I say tear out, I mean small fibers tear loose making the otherwise smooth route rough. OK sand it. Sanding doesn't seem to fix the problem. The surface just does not seem to want to be smooth. Anyone have suggestions or this the nature of the beast?

[Clark Harbaugh]

I ran into the same problem when milling sapele (kin to mahogany) for a table top. For thickness milling, dont take it to final thickness and then use a scraper to work out the tear-outs. I tried a hand plane, but hand tear out problems in the figured areas as well. You can then sand it to the final grit that you want. For router, you just have to take very small cuts. Depending on the shape you are routing, you can use the scraper again.

[Brian Peters]

These are both pretty soft woods and especially sapele for machining it machines beautifully. You shouldn't be getting tear out as you described or have trouble getting it smooth. Can you take some photos otherwise its hard to see exactly what you're talking about.

[Myk Rian]

Take a damp cloth to moisten the surface. That will raise the rough fibers. Sand it again.

[Clark Harbaugh]

These are both pretty soft woods and especially sapele for machining it machines beautifully. You shouldn't be getting tear out as you described or have trouble getting it smooth. Can you take some photos otherwise its hard to see exactly what you're talking about.


I should have mentioned that the tear out I experienced was only on highly figured stock, where the grain ran in multiple directions. The fibers would pull loose, especially when running through the planer. The only problem I had with the router was when I tried to take too much wood in one pass (should know better...). I didn't experience any problems with the straight grained boards.

[Paul Atkins]

This is an age old problem with wood that is figured. Why is anyone surprised when this grain tears out ? The best solution is sharp tools.

[John Harden]

Byron, I work mahogany quite a lot and have encountered something similiar. If I understand you correctly, you're saying that you have these areas of apparent tear out and when you sand them, they don't go away.

Even if you sand off 1/6" or more, they are still there. My experience is this tends to happen on areas of softer wood where the grain interlocks with harder wood. The wood fibers are so soft, they just begin to fall apart.

A drum sander might help, but avoiding wood with these characteristics is often the best choice. The dark, purple, heavy stuff never seems to have this problem for me. Its only the very light weight, lighter colored stuff and it's the lighter colored sections that do this the most.

My advice is to avoid it when you can, but if it's already a part of your project, just do the best you can.

Best I could do was to final scrape and sand the surface, then raise the grain just in these areas, then lightly sand again.

Good luck.

Regards,

John

[Brian Peters]

Yeah sharp tools do help in any case. Take some photos so we can identify the issue though.

[Darnell Hagen]

This is why Honduran mahogany rules, it doesn't get fuzzy like Phillipine.

Apply a coat of your finish (I'm a lacquer guy). This will plasticize the top layer and all those whiskers will sand off smooth. Then second coat.

Butternut is similar.

[Faust M. Ruggiero]

Byron,
I refer to that grain as ribbon. It is in the nature of mahogany. Sand well and use grain filler and the finish will be fine. Thy carving mahogany with ribbon some day. You'll want to take up golf.
fmr

[Byron Trantham]

OK Guys,
I get the message. My experience is normal. In this case the best solution is take to very small cuts with the router. Thanks for your input and help.

[Frank Drew]

Byron,

A lot of African mahogany -- if that's what you're using -- has interlocked grain, which gives it that characteristic ribbon striping. It can machine poorly, but try light cuts with very sharp knives.

I agree with Darnell that S.American mahogany (Honduras mahogany, genuine mahogany, whatever name the dealer uses) is in general milder working and, IMO, altogether a better timber, but it's not as available as it used to be.

[Dave Cav]

I'm making a large china cabinet out of sapele. I haven't had too much trouble with tearout although I did have a couple ends blow out when jointing. I do plane and joint using carbide helical heads, and I think that helps a lot, although this afternoon I was hand planing some edges of boards to clean up tool marks and I didn't have any problems with tearout. I was using my 604 1/2 with a very sharp Hock iron, set very fine.

[Jeff Duncan]

Sounds like your getting the tearout from routing, two things that I try in this situation. One is to make the cuts in 2 passes, the first taking 90% of the material off and the second just lightly cleaning it up. Second if your using inexpensive bits try using a better quality, it does make a difference in the finished cut.
Alternatively if you have a shaper running HSS will give you cleaner cuts.

good luck,
JeffD