Sweetgum - high tendency to warp

[TraditionalTool]

I see a lot of sweetgum being cut down under, BobL plows through plenty of it.

I was curious though, in reading through Hoadley's book, "Understanding Wood", he lists sweetgum as having a high tendency to warp. I haven't heard much about that from folks that cut it regularly, so thought I would ask about that.

Most of the pics I have seen of sweetgum doesn't exhibit checking very much, nor I have seen pics of warping slabs.

Interesting as I know that Southern Yellow Pine most certainly has a tendency to warp and Hoadley lists that as intermediate.

I guess I am just curious, do you folks that work sweetgum find it difficult to work with? Seems for my area tanoak would be closest to sweetgum in the sense of having a high tendency to warp, and I know that it is very difficult to keep tanoak from warping during drying, and if it doesn't warp it will still usually check heavily.

Does the sweetgum check a lot also?

 

[huskyhank]

I've cut a little gum and not noticed any big problems. There are lots of different gums so you have to be pretty specific when talking about them. I'm in Tennessee and I'm pretty sure Australian gum is a different critter from what I have here. Here, commercial use is pulp (AFAIK) and maybe secondary wood for furniture if demand was high. Its not.

As for SYP, its a great structural wood. It can be a bit lively but it has virtues to make up for that. It is very strong and tough so just cull the twisty stuff.

Don't you have trees suitable for your purposes where you live? (just wondering)

 

[BobL]

I see a lot of sweetgum being cut down under, BobL plows through plenty of it.

Husky is right, the stuff you guys call Sweet Gum is, according to me, another name for Liquidambar from the Altingiaceae family and it has a dry Janka harndness of around 850 lbs. I have milled a couple of LiquidAmbar logs and they were both pretty soft compared to the other stuff I mill. The stuff I mill is from the Eucalyptus, Acacia, Allocasurina or Corymbia family and they have Janka hardnesses around 2000+ lbs.

In Oz, we tend to call anything in the Eucalyptus (800+ species) or Corymbia (# of species still being determined) family "gums" because they make lots of gum or resin!

Some of it is quite spectacular!

 

[huskyhank]

%^$&^%$*#^@(&

BOB! whats that picture????!!!!!!!

 

[BobL]

%^$&^%$*#^@(&

BOB! whats that picture????!!!!!!!

That sir is one of many jokes I played on BIL. Sometime after we built the BIL mill I was milling a Corymbia (Bloodwood) and it had these magnificent half fist size pockets of this clear blood red resin. It's apparently sightly toxic but one is drawn to play with it like mercury and so a plastered some on the back of my hand and placed it near the chain got someone to take a few photos which I emailed to BIL (unfortunately my sister opened the email and got a bit of a shock). Anyway I was just paying BIL back for the time he sent me gory pics of his back operation under a fake email name and address!

Here's the original post back in 2008. Check out the fiddle in that wood.

 

[TraditionalTool]

Husky is right, the stuff you guys call Sweet Gum is, according to me, another name for Liquidambar from the Altingiaceae family and it has a dry Janka harndness of around 850 lbs.

What Hoadley has in his book is listed as a hardwood, so it's gotta be harder than 850, IMO, maybe not.

I've seen pics of what you call sweetgum and it looks pretty red to me. What is in this thread?

In Oz, we tend to call anything in the Eucalyptus (800+ species) or Corymbia (# of species still being determined) family "gums" because they make lots of gum or resin!

Mostly curious as that stuff doesn't look like it's split/checked very much, and wasn't sure...maybe that isn't sweetgum...I thought somewhere you mentioned that was sweetgum, but I don't see any mention in that thread.

 

[BobL]

What Hoadley has in his book is listed as a hardwood, so it's gotta be harder than 850, IMO, maybe not. I've seen pics of what you call sweetgum and it looks pretty red to me. What is in this thread?

This is Eucalyptus Marginata. It grows in an area covering about 300 miles by 200 miles in the very south west corner of Western Australia. It prefers growing in an ironstone gravel subsoil - most of which has been cleared for farming or bauxite mining, or milled out, so there is practically no virgin forest left. It needs about 30+ inches of rainfall a year to thrive but there are dwarf sub-species that can grown in less than this. It has a variable green hardness but is typically around 1300+ lbs janka green and 1820 when dry but I have cut trunks of this stuff that have been much harder than this. This is considered a soft Eucalypt.

More arduous and exciting to cut is Eucalyptus gomphocepalus or commonly referred to as tuart.
Janka hardness green 2100 lb dry is 2400 lb
BUT
that is only half the story because it.
- absorbs silica under the slightest stress and all these trees have been under stress for the last 40 years due to changing rainfall patters and it.
- releases a dark brown black resin that gums up the chain very quickly. I run double aux oiler oil to counteract this.
So in practice these make it harder to cut than woods of around 2500 lb hardness.

Then we can move onto Eucalyptus Wandoo (commonly called Wandoo).
2200 lbs green and 3200 dry - its very termite resistant and there are fences around made of this stuff that are more than 100 years old. Old wandoo turns a wonderful chocolate brown colour.

Mostly curious as that stuff doesn't look like it's split/checked very much, and wasn't sure...maybe that isn't sweetgum...I thought somewhere you mentioned that was sweetgum, but I don't see any mention in that thread.

It depends strongly on how it is dried.

 

[Backwoods]

I have not milled a lot of “Sweet gum” but what I have milled sprung in the drying process. The rest of the wood in the barn dried nicely but the “Sweet gum” (Yard tree from a nursery no one knows for sure what sub species it was.) moved in all directions making only usable for small projects.

 

[jdrum]

back in the seventys i worked in a furniture factory for a couple of years and they used sweetgum heartwood to make walnut furniture, when the stacks came out of the kilns the planks were a little twisty but not bad. it's when you get to the knots that every thing goes haywire, they move in every direction but where you want.
the only other place i have seen much sweet gum used is in pallets,and dunnage, i have salvaged a few of them 4x4s that look like corkscrews, and some as straight as a string. made some nice jewlery
boxes.

jim