Smoking Dragon

[PuzzledMoose]

OK I've read about problems with wood burning but haven't experienced it before, other than a very small amount on some cherry.

I just started to cut a Judy Peterson dragon puzzle and I thought the wood was going to ignite - a very impressive plume of smoke ... truly worthy of a dragon!!!

I was cutting mahogany, which i've never cut before, a little under 3/4 inch thick, with a no3 FD blade, saw on a little over half speed.

I've read in various places that clear packing tape will stop the burning - I just don't have any right now! Any other solutions?

Ian

[Gill]

Hi Ian

I presume the wood is burning as you make turns? The chances are that you're turning the wood too quickly for the size and type of blade, and the friction is making the wood burn. You could use a smaller blade, although a #3 should be able to cope (sic) with 3/4" mahogany. Another trick would be to employ a skip tooth blade which would give the swarf a better chance to dissipate as you cut.

Finally, you could use the 'backing off' technique, which I find difficult to describe . Nibble a little of the wood as you turn into it, then back off away from the cut, rotate the wood slightly into the direction of the turn and repeat the process. You'll be surprised at how acute a turn you make without burning.

Gill

[PuzzledMoose]

Thanks, Gill. You were right it was the turns for the puzzle tabs that were the problem. The no 3 blade seems to be cutting it fine without struggling and I've cut oak OK with a no 3 - is oak as hard as mahogany?

I was trying not to go bigger with the blade. The puzzle pieces fit nicely with a number 3 but seem to "sag" a little with anything bigger.

I'll have another try tomorrow - on a bit of scrap first - and order some skip tooth blades to try.

Ian

[Gill]

Hi Ian

Gosh, it's a long time since I cut mahogany - in fact, I can't recall ever cutting it! Since most oak has a coarser grain than most mahogany, I should imagine the swarf would disperse more easily from oak and there'd be less of a propensity to burn. I certainly find it easier to burn ash and maple, which are close-grained woods, than I do oak, which has a more open grain.

I'm sure someone's ready to tell us which woods are harder than which but it's not just hardness that governs how easily wood will cut, in my experience.

Why not try the 'backing off' method tomorrow, Ian? It takes a little practice at first but it's worth learning the technique.

Gill

[Indiana saw man]

Great info, gill . i do a lot of stack cutting i use a lot of cherry and oak and i have found out by usuing wax paper inbetween the layers helps a lot the back cutting works the best for me .

The saw man

[Forester21]

Mahagony is a softer wood than Oak, but as Gill mentioned you also have the wood grain in oak that may make a difference in the burning.
First thing I would do is change blades.... but I have had quality control issues with my blades lately, so that might not be your solution. I've tried the clear packing tape and could not tell a difference.
so, a lot of rambling and not much information for you!!
Theresa

[Jediscroller]

I cut a lot of mahogany items as it's one of my favorites to work with. There are different types of mahogany though so a lot would depend on which type you're using. Genuine mahogany is very easy to work with as is African mahogany. Brazilian mahogany is as hard as a rock. I've never had a problem with burning but I always use clear packing tape over the pattern. My experience is quite different than Theresa's in this regard. I took a small piece of cherry, put packing tape over one section and nothing over another. I then cut a straight line through the 2 sections and had significant burning in the untaped area. As a result, I'm a firm believer in the benefits of clear packing tape.

[PuzzledMoose]

OK - I covered the piece with packing tape, changed the blade, slowed the speed down a little more - and tried Gill's "backing off and nibbling" approach". I'm not sure I've got the hang of the latter yet!

Anyway no more plumes of smoke and charred wood - just a tiny bit of scorching so something about all those suggestions worked ... thanks everyone ..

As far as what kind of mahogany it is - sorry no idea - I bought it from the offcut bins at East Coast Speciality Hardwoods down in Halifax and it just said Mahogany!For the most part my skills at figuring out what kind of wood I have in my hand are similar to my skills in nuclear physics -ie Zilch! Slowly learning - has anyone written a Dummies guide to identifying wood?

Ian

[lucky788scroller]

Using a blade without reverse teeth also would help you, if currently you are using one. dale

[Rolf]

I have been cutting a lot of mahogany lately ( free wood that I have re-sawed and planed) I also have some Brazilian black walnut, that is hard.
I use Olson 2/0 and 2 reverse and have no burning issues. Gill is right about the corners. Technique becomes an issue you do not want the blade twisted rubbing against the sides it will really heat up (as you already know) Rick Hutchinsons web site has some short videos on some of the ways for cutting tight corners.

[workin for wood]

If your mahogany is burning when you cut it, I'm guessing it's Mahogany Santos, which is commonly used in hardwood flooring. It's pretty dense and cuts like a rock. Seems impossible to plain it, I have to take mine to the local cabinet shop and pay them to run it through a drum sander. It's difficult to stop the burn on that wood because it is like cutting steel. Most mahogany's are ver soft, usually softer than pine, and those mahogany's are about impossible to burn. the Santos Mahogany is very common, and in my oppinion it has the most beautiful color and finishes the best.
There are lots of books to identify tree's, but lumber itself is much more difficult to identify. I don't believe there is a book that could ever honestly do that task. There is a book called the Encyclopedia of wood, and it has a reasonable selection of woods in it, with a picture of the wood, name of wood, properties, uses etc. But you can't expect to pick up a piece of wood, lets just say red oak, put it next to a picture of red oak, and expect them to look the same. Not only that, but there's well over 100,000 possibilities of wood in the world and so many of them look the same as the next.

I feel pretty safe saying that you are using mahogany santos, because there are only 2 mahogany woods that are common to find in a lumber store, Santos and American. American is pretty soft and often called "Genuine Mahogany", and it comes from mexico and south America. Santo's Mahogany also is from South America. Sometimes you'll find African Mahogany, but the chances are good that your supplier is a liar, because the supplies in africa are alot smaller, and exports are more difficult. I'm always skeptical when I go to a lumber yard because sometimes they try and pull some wool over your eyes, and so you never really know. It's unlikely but still possible to have african mahogany. Anyhow, those are the two normal mahogany's but there is over 100 other possible mahoganies that exist.

[Jediscroller]

Jeff,
I'm curious about why you would think that if your lumber supplier carries African mahogany along with genuine, Santos, and any of the other myriad possibilities of mahogany he would be a liar. I was under the impression that African Mahogany is another name for Sapele? My local lumberyard regularly stocks this at somewhat less than "genuine" mahogany (currently $5.95/bd. ft for Sapele vs. $8.80/bd ft. for genuine mahogany). Their price list is here.
The woods have very different looks and grain patterns.
Just curious.

[workin for wood]

I buy most of my lumber locally because of convenience, but when I have opportunities to go elsewhere, I look and buy from them too. My local people are some real schyster's. I've compared lumber and what they are supposed to be called from several places and quite often find differences. First I find the contradiction, then I do some online and encyclopedia research to investigate who is wrong. In the end it probably isn't that important, but I like to know just what it is that I actually have. And my local yard does have sapele which is an african mahogany, but that's not the genuine african mahogany that is desirable in furniture making.
As far as what lumber is, my local company probably can't be blamed because they buy it from another company who tells them what it is, and they buy it from other sources and so on down the line. But I could still write a book on how they try to rip me off.
In canada I had a supplier that actually imports the wood himself from different countries. You can bet I visit him anytime I go back to visit family. He actually goes to the countries and selects the actual trees he wants, and he is a major fountain of knowledge when it comes to wood.

[Tony Burns]

OK I've read about problems with wood burning but haven't experienced it before, other than a very small amount on some cherry.

I just started to cut a Judy Peterson dragon puzzle and I thought the wood was going to ignite - a very impressive plume of smoke ... truly worthy of a dragon!!!

I was cutting mahogany, which i've never cut before, a little under 3/4 inch thick, with a no3 FD blade, saw on a little over half speed.

I've read in various places that clear packing tape will stop the burning - I just don't have any right now! Any other solutions?

Ian

Puzzledmoose - Cherry is very hard to cut because of all the resins that are in it , as well its density ( You should try Rock Maple it has its own headaches ) most burning problems come from friction or getting caught in a tight place, or keeping the blade in one area too long -a finer blade such as a #3 ( not all #3 blades are alike ) The more control you have over your cutting the less burning you will get , i mean to say more of an even feed speed and better control of what your cutting , which is gained by experience ( or over time )I use music alot as a metaphor , but the more practice you get, the better you get ( just like playing an instrument ) at cutting woods like Cherry - Believe me Cherry is not my favorite wood - You should try cutting Brazilian Mahogany - its like cutting a Rock.

Tony Burns
Scrollsawpuzzles.com