Replies

1. 
   hammer1 | Aug 02, 2005 03:21am | #1

   Mahogany can have some nice straight grain and some twisting erratic grain depending on the individual pieces. It is very common, with all species of wood, when ripping wide pieces into narrower ones, for the rip to bow. You have released the dynamic tension within the board.

   I don't mill my lumber until I'm ready to use it. After milling, I keep it evenly stickered and let the air circulate. Milling techniques can have a big effect on stability. If you take more off one face than the opposite, bad things can happen. Just like the bowed rip.

   Routers and shapers can tear out areas no matter how slow or small a bite you take. Erratic grain is particularly difficult. Sometimes, a scoring cut with a saw or knife can help with some profiles. If you are getting tear out on the whole length, you may not be reading the grain correctly. The grain doesn't always run the same as the annual growth rings. You have to look for the direction of the small pores.

   Many similar species are labeled mahogany. I used some stuff that looked like ordinary mahogany, andiroba, but was impossible to eliminate tear out on. The only thing that would work was abrasives. Because the mahogany group is open grained, it can get hairy, rough and splintery.

   Beat it to fit / Paint it to match

1. 
   Indigo1557 | Aug 03, 2005 05:22am | #5

   Hammer...I had to smile when I read your post.  I've been working with some big boards of mahogany lately and have watched some piece warp before my eyes as they come out the other side of the blade.  Weird to watch, sorta funny in a sick way, and frustrating as all get out.

   Alison

2. 
   WillGeorge | Aug 03, 2005 08:34pm | #7

   Mahogany can have some nice straight grain and some twisting erratic grain depending on the individual pieces. It is very common, with all species of wood, when ripping wide pieces into narrower ones, for the rip to bow. You have released the dynamic tension within the board. I'm not sure this really works BUT... I do it on wide (expensive) wood I have used for doors...I take the slab.. Mark for the rip... I saw a 'curf' on each side of the stick about 1/4 of the thickness.. I use a spray bottle with distilled water in it and just mist the 'curf' on both sides.. NO SOAKING!.. I sticker on a bench for a day or two and then cut...YES, sometimes I still get a bow but I 'think' it helps.. Since I have done this I do get a lot less sticks that bow on me...I could be wasting my time but at least I think it works so I'm happy!

1. 
   hammer1 | Aug 04, 2005 02:12am | #8

   That's a process that I haven't heard of, Will. Maybe adding a wish and a prayer might help, too. I'm hoping and praying most of the time, anyway.I rip oversize while still in the rough. Many projects require short pieces, so, if a rip or two goes whacky on me, I cut it into short pieces and then mill them. One thing for sure, the woodworking process can always have a surprise or two waiting for you. You have to learn to roll with the punches.Beat it to fit / Paint it to match

2. 
   creekwood | Aug 02, 2005 02:45pm | #2

   I second what hammer said. You can have a beautiful board, nice and square, and cut into smaller dimensions, and everything goes "kattywampus". There can be some hidden stress that you just can't see until then. Even Honduras mahogany can have this stress, but the others that pass off as mahogany seem to have more.

3. 
   brianmexico | Aug 03, 2005 12:44am | #3

   Alywood,

   I use a lot of mahogany and spanish cedar in my shop and I use a few rules when cutting.

   When routering if you suspect you can get any chatter, rough edges or tear-out start with a climb cut (with the rotation of the bit) and remember to hold onto the router carefully because this can be funky. Leave the last pass for a regular cut.

   Always mill your first pieces down too wide so that you can joint them straight and rerip on the saw to get your good piece. This can create waste but not as much as a useless piece that will no longer work in your project.

   Good luck,

   Brian

1. 
   aylwood | Aug 03, 2005 01:25am | #4

   Thanks for the good advice. For the moment i'm going to back off from the mahogany. I've a cherrywood blanket chest to make alsoa hexagonal display case to make in maple. ( the value of daughters / wife's requests) but i will heed your guidance.

   thanks

1. 
   Dan | Aug 04, 2005 02:51am | #9

   Aloha,

   I'll second what brianmexico said but add this.  I try to anticipate how long the pieces will be for my project then cross cut to approximate length before ripping.  Takes a bit of planning but I especially like the outcome on rails and stiles: I get a better color and figure match.  Pretty difficult to rip an 8' piece without getting some bow.Mistakes are but an opportunity for fresh design!

4. 
   mikegagne | Aug 03, 2005 06:55am | #6

   Aylwood. you have "discovered" khaya or African Mahogany. Cool isnt it? Its reactive in some cuts, fine in others. aloha, mike

5. 
   philip | Aug 04, 2005 06:03am | #10

   Aylwood,
   The fact is that you guys over there in the U.S of A are spoiled silly with all the quality timbers available from all over the world <g>.
   Seriously now, don't be fickle with that Mahogany. If it is Khaya species I can tell you that I have worked lots of it and what you describe is not unusual, and a small price to pay. You will more often than not find that it settles down shortly after you have machined it,especially if you have stickered it temporarily to allow even access of surrounding air.Antway if you are nervous you can always do as others have suggested-cut slightly oversize etc.It can be a bit otherwise if machined improperly-but again not a train smash by any description-dammit, wood is wood ,every piece is different, just to make it more interesting.If you can't get good results when routing it then I suspect that the fault lies not in the timber.
   Also, and more importantly, Khaya and other true mahoganies are "stable in service" to quote the trade vernacular,i.e they settle down and stay put. Andiroba is not Mahogany....
   Visualise that cabinet in Mahogany, nicely polished. I attach a picture of a table I made 30years ago-basically polished with shoe polish-so today what can you do with all the fancy polish options available?

   
   

   ---

   Edited 8/3/2005 11:09 pm ET by Philip Marcou

   
1. 
   WillGeorge | Aug 08, 2005 08:55pm | #11

   Shoe Polish! Was it Kiwi by any chance...???The fact is that you guys over there in the U.S of A are spoiled silly with all the quality of our women... YA BET!

1. 
   philip | Aug 09, 2005 01:10pm | #13

   Hey Willie: that was a long time ago when Rhodesia was a country and Kiwi was a land far away that always tried (and usually failed) to beat us at sports like rugby and cricket.<G>

2. 
   roninfante | Aug 09, 2005 01:20pm | #14

   I like the rug too!

6. 
   VomSorb | Aug 08, 2005 10:38pm | #12

   I've worked with African Mahogany so roey it almost couldn't be scraped.  That's a money loser for me so I don't use it anymore. 

   The thought of trying to machine it with anything but brand new router bits, planer, and jointer blades makes me cringe. 

    

1. 
   philip | Aug 09, 2005 01:24pm | #15

   ....so "roey" it couldn't be scraped---- goodgodman, that is an oblique reference if I ever saw one!See what I mean when I say you guys are spoilt with all the choice timbers under the sun, and you sniff at the "roey" stuff. <g>
   Btw, bits , blades, knives etc don't have to be new-they require to be sharp and well maintained.