cutting

[Sean Boyle]

I have not turned a lot of green wood and nothing this size approx. 13 inch wide by 6 deep what is the best way to cut these round. Chain saw or Band saw I have a 14" band saw but how do you mark a circle on the bark side or is there a jig I could make

 

[Robert Taylor]

cutting blanks

you can use either a chainsaw to knock the corners off, or I use cardboard disks and an awl to cut them to round on the band saw. The flat side should be on the saw table.

 

[hockenbery]

Sean,

I use hardboard disks on the bandsaw

I do a rough line up of the grain. You can use a square to mark both ends of the 1/2 log above the center growth rings.
Then draw a line between the marks and make your center along that line.

I the use a 1 1/4 Forstner bit to drill to solid wood on at the top center
I never put a center into the bark since it has no structural integrity.

I use a scratch awl to pin a hardboard disk of the desired diameter and cut the blanks round on the bandsaw.
I cut close to the dis without cutting into too often. After a while all my discs end up going into service for a smaller diameter.

If I'm turning natural edge bowls or hollow forms I use my center hole for the spur drive.
If I'm turning a cut rim bowl I use the hole for the tailstock center.
Also for these bowls if I want to have room to move the tail center to line up the grain, I would make a wide spot with the chainsaw or set the depth on the drill press and drill a bunch of holes using the drill press like a planer.

I have attached a couple photos. The first two are do a hollow form blank prep. The third is for a natural edge crothch bowl.

Al

 

[odie]

I have not turned a lot of green wood and nothing this size approx. 13 inch wide by 6 deep what is the best way to cut these round. Chain saw or Band saw I have a 14" band saw but how do you mark a circle on the bark side or is there a jig I could make

Sean......

Just something to consider here.......

I do not turn many natural edge bowls, but I have done a few in years past. When I did do a few, I made up a special jig to find the exact center I wanted on the bark side of a bowl blank. Once you find this exact pivotal point in the center of the bowl you envision, you can probably figure out how to cut it circular on your own, according to the resources you have available.

What I did was use a retractable plumb bob to hang straight down to the center of concentric circles. (Either drawn on a sheet of butcher paper, or one of those plastic center finding jigs you've seen advertised.) Once the plumb bob is positioned so that it points exactly to the center point of the sheet with concentric circles, it's raised so that the turning block can be positioned on the sheet to best take advantage of the shape, grain, and points of interest in your bowl. You then simply lower the plumb bob down to the bark level, and you can mark the center of the bowl.

I have a 3 1/2" (I think) Forstner bit that is used to take the bark down to the wood at that point. The size of the Forstner is just right to fit one of my 3" center screw faceplates.

Note: You can mount the faceplate, and install the bowl block to your lathe spindle prior to cutting it circular. With it mounted, it's easy to make a circle on the flat side of the bowl block. This may not help you at all, because the circle will be on the wrong side of the BB for cutting it on the band saw.......but, if you have a way to make it round on the lathe, it might help.

Anyway, I'm not speaking from experience here......only done this a few times in the past.

ko

 

[JeffSmith]

I do both what's described in the other posts. For some pieces I'll center the growth rings and cut to round on the bandsaw using a hardboard round the right size. If it's a shallow blank like you show, and I've still got the chainsaw out, I'll just knock off the corners and go straight to the lathe between centers so I can move it around until the grain is centered the way I want.
Shallow bowls are pretty easy to rough to round on the lathe as long as the corners are off, and it's a lot faster, at least for me.

 

[hockenbery]

Two additional comments

For pieces to tall for the bandsaw, use disks, a big compass, or a marker on string tied to my scratch awl and make two circles on the flat face.
One the desired diameter the other 2" larger in diameter.
Then with the flat face up I use the chain saw to cut away most or all of the big circle and don't cut any of the desired circle.


Also for the oblong natural edge bowls I don't cut circles but make the blanks 30-60 % longer than they are wide.
An 8" diameter half log I would use a disk with a diameter of 10 to 12" This leads to a nice oval shape.
Also I tend to make shallower bowls a bit more oblong
I have done some bowls with a length of 12" and a diameter of 4" They are fun and challenging but they don't look as nice to me. But it is something everyone should do one of.

For natural edge bowls that will be taller than wide, I cut the blanks round.

Al

 

[Gretch Flo]

Sean-I do alot of natural edged bowls. I have 1/4" plywood rings, made from 4 1/2" to 13" diameter in half inch increments with a hole in the center.
I place the appropriate size ring to maximize the wood diameter or area of the wood that I want to include (missing some knots or cracks) and then use white chalk to mark the bowl bark. It's rough and not rocket science ( tried using the wood rings on the blank while bandsawing as has been pictured above, but quickly learned I was injuring them!!!!). If I have white birch I may use a sharpie or a different color chalk. Gretch

 

[Breck Whitworth]

My 2 cents

Sean,
I turn both green and dried wood, what I have learned is unless you have a 1/2" 3 TPI bandsaw blade to cut thick green wood blanks into a round, I would suggest using the chainsaw for the green wood. For dry wood a standard blade (1/4" x 6 TPI) works exceptionally well for cutting rounds. Do what ever works best for you but with a little practice you can trim green wood with your chainsaw to the point roughing the blank is very easy. For dry wood I always use my band saw to cut it into a round. I hope this is some help to you, best of luck

 

[Gretch Flo]

If the wood is really wet, it'll gum up the bandsaw . WD 40 applied to blade first helps, Gretch

 

[john lucas]

I use the plywood discs that I screw onto the wood. For hollow vessel blanks that can be awkward or dangerous on the bandsaw I chainsaw them as close as I can to the disc. This leaves a multifaceted surface but it doesn't take long to round out on the lathe. For bowls I usually but the blanks on the bandsaw with the discs for anything under about 16". larger blanks are cut on the chainsaw with the disc. I do occasionallly hit the disc with the bandsaw or chainsaw but they have lasted a long time. I use 1/4" luan plywood so it's just a matter of a couple of minutes to make another disc if I do screw it up to bad to use.
For natural edge bowls that I want oblong I don't use the disc at all. I simply cut the length on the bandsaw. Then I mount them between centers and adjust the headstock and tailstock centers until the blank is centered the way I want it. Usually with the long ends being parallel to the headstock vertically and adjust it side to side to center the growth rings. I may have to make a few cuts and then readjust once I see where the rings really appear but that's why I mount it between centers.

 

[Sean Boyle]

Thanks everyone this is going to be todays project

 

[Bill Boehme]

I roughed out an elm bowl yesterday (13" diameter) and the half-log was a bit larger than yours. I just left the corners on and turned them away. It isn't the fastest way to go obviously, but it can be done. I drilled a couple holes for the drive spur and the live center nose and flattened the face between centers. After that, I turned a wide mortise in the flat face so that I could hold it in the chuck using either compression or expansion. I always go for compression unless there is a reason not to. Once in the chuck, I could be considerably more aggressive in knocking the corners off. The bark was coming off in big hunks so I pulled the rest of it off before continuing. I would have preferred to use my bandsaw to get it round, but it is partially disassembled. Here is an "after" picture. I didn't think of getting a "before" shot.

 

[Sean Boyle]

Bill

I turned 1 of the pieces Saturday to basically what looks like yours. The piece was quite wet to the point is was splashing me and my face shield. Once off the lathe I but it in a paper bag and set it aside. Bill is that what looks like anchor seal or something else and should I be doing anything else to prevent cracking

 

[Bill Boehme]

Bill

I turned 1 of the pieces Saturday to basically what looks like yours. The piece was quite wet to the point is was splashing me and my face shield. Once off the lathe I but it in a paper bag and set it aside. Bill is that what looks like anchor seal or something else and should I be doing anything else to prevent cracking

This piece was about half way between wet and dry so I usually Anchorseal anything that isn't completely dry if I plan to let it completely dry before I do the final turning. Our club buys Anchorseal in bulk (55 gallon drums) so it is a lot cheaper than buying it by the gallon. I think that this bowl should be ready for finish turning by June. I'll weigh it periodically to see when it is ready.

 

[john lucas]

I usually anchorseal just the endgrain areas and sharp edges. This is where the bowl loses moisture the fastest and thats what makes them crack. You need even drying. I also use a paper sack or box with the lid closed but not taped.

 

[Bill Boehme]

I usually anchorseal just the endgrain areas and sharp edges. This is where the bowl loses moisture the fastest and thats what makes them crack. You need even drying. I also use a paper sack or box with the lid closed but not taped.

I've thought about that, but how do you decide where end grain stops? On a round roughed out bowl, there is a bit of end grain exposed most of the way around. By the time that I apply Anchorseal to roughly half of the bowl, I figure what the heck ... why am I being so cheap, there's no harm in doing the whole thing. I decided to use Anchorseal like John Lucas is paying for it. Check your mailbox -- an invoice should arrive any day now.

Seriously, a gallon of Anchorseal will last me quite a while ... typically six months or more.

 

[hockenbery]

I quit using anchor seal on rough outs around 1998. Bowls treated with anchor seal would take 10-12 months to dry to 10% MC. Using paper bags the rough outs get to 10% MC in 6-8 months. I still use anchor seal on log sections to keep them from drying out for a few months. Anchor seal is effective, messy, expensive and slow. Paper bags are effective, time consuming, clean, free, and faster.

My method is to wash the bowl as soon as it comes off the lathe, towel dry, write the date and species on the bowl, put in one bag and slide a second bag over the opening. Place the bag so that the bowl is on its side resting on the rim. The change the bags every day for a week until the bags are not damp. If I see any mold, I wipes the bowl with clorox and put the bags it came out of into the recycling. When the bags are dry the threat of mold is gone. I then leave the bowl on its side on a shelf of about 4 months, then take it out of the bag and stack on a shelf upside down. I stack bowls on top of each other but do not nest them.

Al

 

[Bill Boehme]

Where do you find paper bags? They seem to be more scarce than hen's teeth around here.

Anchorseal is still pretty cheap for members of Woodturners of North Texas. Your area is probably much more humid than it is here. Bowls coated with Anchorseal usually dry in three or four months here.. Large thick ones might take six months (based on my experience with one 18" diameter box elder bowl that was rough turned to 1½" thick). Most of what I turn is mesquite or dry maple so I don't need Anchorseal that often.

 

[hockenbery]

Where do you find paper bags? They seem to be more scarce than hen's teeth around here. Anchorseal is still pretty cheap for members of Woodturners of North Texas. Your area is probably much more humid than it is here. Bowls coated with Anchorseal usually dry in three or four months here.. Large thick ones might take six months (based on my experience with one 18" diameter box elder bowl that was rough turned to 1½" thick). Most of what I turn is mesquite or dry maple so I don't need Anchorseal that often.

We have grocery stores in Florida. I think I saw one in Austin.
We just say paper please and the bagger puts the groceries in the paper bag.

 

[Sean Boyle]

I have rough turned both bowls now and have put anchor seal on both. I am in Northern Ontario and below freezing for the winter. My shop has 2 sides 1 heated with a pellet stove so it is dry heat with temp set to 50 F at night and up to 70 F while working the other half is unheated but with heat loss from the siding door it never goes below 32 F liquids never freeze how ever humidity would be much higher as this is the side the thaw out my snow machines on. What would be the better side to store the bowls

 

[john lucas]

Bill. It's mostly because anchorseal is messy. I just estimate the end grain and over paint. Al. With anchorseal and paper sack I don't have to touch them again until dry. Since I do t turn many bowls I do t worry about how long it takes to dry. I always have lots of dry ones on the shelf if I feel the need to finish turn one

 

[hockenbery]

I have rough turned both bowls now and have put anchor seal on both. I am in Northern Ontario and below freezing for the winter. My shop has 2 sides 1 heated with a pellet stove so it is dry heat with temp set to 50 F at night and up to 70 F while working the other half is unheated but with heat loss from the siding door it never goes below 32 F liquids never freeze how ever humidity would be much higher as this is the side the thaw out my snow machines on. What would be the better side to store the bowls

Sean,
You want to slow the drying. If the heated side is below 30% RH, I would put the bowls in the unheated side to dry for a couple of months then bring them into the heated side.
The idea is to slow the drying. The anchor seal does this but in super dry space the bowl might still loose moisture too fast.

Al

 

[hockenbery]

Bill. It's mostly because anchorseal is messy. I just estimate the end grain and over paint. Al. With anchorseal and paper sack I don't have to touch them again until dry. Since I do t turn many bowls I do t worry about how long it takes to dry. I always have lots of dry ones on the shelf if I feel the need to finish turn one

John,
I'm in much the same boat. I rarely return bowls these days. I might have a hundred dry rough outs.
I still rough out 2-3 bowls a year. Those I do for empty bowls are mostly natural edge pieces.

Al

 

[Tom Beatty]

paper bags

Where do you find paper bags? They seem to be more scarce than hen's teeth around here.
Bill
Frozen food isle at walmart, only one size but better than nothing

 

[john lucas]

Our Sunday newspaper used to have paper sacks that was some sort of add. I saved those and still have about 20. A decent alternative that I used to use is the Sunday paper itself. I would wrap it in about 3 or 4 layers and then just tape it shut. Works for smaller bowls. Not so well on large ones but then its hard to find paper sacks fom20 in h bowls.

 

[Bill Boehme]

I have rough turned both bowls now and have put anchor seal on both. I am in Northern Ontario and below freezing for the winter. My shop has 2 sides 1 heated with a pellet stove so it is dry heat with temp set to 50 F at night and up to 70 F while working the other half is unheated but with heat loss from the siding door it never goes below 32 F liquids never freeze how ever humidity would be much higher as this is the side the thaw out my snow machines on. What would be the better side to store the bowls

Sean,
You want to slow the drying. If the heated side is below 30% RH, I would put the bowls in the unheated side to dry for a couple of months then bring them into the heated side.
The idea is to slow the drying. The anchor seal does this but in super dry space the bowl might still loose moisture too fast.

Al

Relative humidity (RH) is a function of temperature so you can't compare RH at the two very different temperatures when it comes to drying wood. Warm air holds a lot more total moisture before it reaches saturation, so even if the RH on the cold side where the temperature is just above freezing happens to be greater than the RH on the warm side, the wood is very likely to dry out faster on the cold side. I don't think that your snow machine would contribute much to the RH unless it is warm enough to generate visible vapor. If you have a hygrometer, you could see what the RH is on the cold side. Unless it is really high, the warm side might slow down the drying better than the cold side. However, in the real world with Anchorsealed wood the difference probably isn't enough to worry about.

 

[hockenbery]

Relative humidity (RH) is a function of temperature so you can't compare RH at the two very different temperatures when it comes to drying wood. Warm air holds a lot more total moisture before it reaches saturation, so even if the RH on the cold side where the temperature is just above freezing happens to be greater than the RH on the warm side, the wood is very likely to dry out faster on the cold side. I don't think that your snow machine would contribute much to the RH unless it is warm enough to generate visible vapor. If you have a hygrometer, you could see what the RH is on the cold side. Unless it is really high, the warm side might slow down the drying better than the cold side. However, in the real world with Anchorsealed wood the difference probably isn't enough to worry about.

Bill,
I agree is best to use a hygrometer.

It is my assumption that the air inside the heated area and the unheated area both have the nominal moisture volume of the outside air.
The saturation point of the heated area is greater than the saturation point of the cold area.
If this is true the RH of the cold area is always more than that of the heated area.

RH= 100 x ( moisture volume)/(saturation moisture volume)

is there a flaw in my thinking?


Al

 

[Bill Boehme]

Bill,
I agree is best to use a hygrometer.

It is my assumption that the air inside the heated area and the unheated area both have the nominal moisture volume of the outside air.
The saturation point of the heated area is greater than the saturation point of the cold area.
If this is true the RH of the cold area is always more than that of the heated area.

RH= 100 x ( moisture volume)/(saturation moisture volume)

is there a flaw in my thinking?


Al

It occurred to me about a half hour ago that I had a flaw in my logic, so I logged on to correct what I said. I was thinking about two separate situations such as two different days where we wouldn't be heating cold air, but in this case we are referring to the same air mass with the same absolute amount of moisture. So, yes you are correct and I didn't realize my mistake before you busted me.

 

[Sean Boyle]

Bill

it looks like you theory is correct the RH on the unheated side is 39% while on the heated side it 23%. My pellet stove draws it combustion air from outside and exhaust outside so there is very little air exchange with outside air. It is a very dry heat

I have been storing the bowls on the unheated side and will move them forward in the spring

 

[Hu Lowery]

craftpaper or newsprint

Where do you find paper bags? They seem to be more scarce than hen's teeth around here.

Anchorseal is still pretty cheap for members of Woodturners of North Texas. Your area is probably much more humid than it is here. Bowls coated with Anchorseal usually dry in three or four months here.. Large thick ones might take six months (based on my experience with one 18" diameter box elder bowl that was rough turned to 1½" thick). Most of what I turn is mesquite or dry maple so I don't need Anchorseal that often.

Bill,

Rolls of the same type of paper are pretty cheap in the paint department of the box stores. Masking paper or craftpaper. Newsprint is good too. If you have a big newspaper nearby they are often happy to give you the ends of rolls or used to be. I would rather buy a roll of paper for twenty dollars or so than spend three times that plus the time chasing it. My slaughterhouse/meatmarket still uses paper bags and I get a few from there but not enough. Starting all over with my river of wood so it takes a lot to get started.

Hu

 

[Gerald Lawrence]

In theory roll or flat paper would need to be sealed on the edges to create an effect similar to a bag. Or I guess it could be folded repeatedly. I am also thinking cardboard box is a good alternative and as a matter of fact the only thing for larger bowls in my experience.
Our Grocery here is about the only place with paper regularly. Another thought use paper gift bags.