Turning Blank Preparation Help Needed

[Tom Davis]

I’m not a turner, my wife is. However, I have a truck, chainsaw, band saw, a relatively strong back, a weak mind and am easily manipulated - so I’m in charge of the portion of the turning process from tree to turning blank. I’m not completely new to this, I’ve done it for several years now and I’ve read a lot and watched various videos on the process. However I’m just not doing it right. I continue to end up with a large percentage of blanks that check before they are turned.

Some background: My wife likes to work on large pieces so I am typically working with logs 16” – 24” in diameter. We are in South Georgia and the species I typically have to work with are Cherry, Bradford Pear, River Birch, Magnolia, Pecan, and Camphor.

So I have several questions:

How quickly should you mill from a log to a blank? I’ve tried immediately cutting logs in the blanks as well as sealing the ends of logs with Anchorseal and cutting blanks several months later. My checking results seem consistent regardless of approach.

I’m making an effort to remove the pith from the center of the log. My wife has talked with other turners/instructors, many who say this is not necessary. What’s your experience?

Sometimes my chain sawing produces blanks that don’t have parallel faces. I get fussed at because it takes her longer to true up the blank. While I’m doing better, should I just tell her to shut up and stop abusing the help and live with it?

After chain sawing and band sawing the blank, I seal the entire blank. Is it necessary to seal the entire blank or just the edges (end grain)?
After the blanks are sealed, they are stored on shelves. Should they be stickered?

Any suggestions are appreciated. I feel like I’m wasting a lot of effort and wood with the approach I am taking.

Thanks

Tom

[Prashun Patel]

I have found it necessary to remove the pith.

I seal the edges and the face.

I don't sticker my blanks. I stack them. But I do move them and look for mold every couple-so-often.

I find it best to get from log to roughed out bowl asap. But in reality, I've had them sit for months at various stages of production from log to blank to bowl, with success.

Where are you storing your blanks? I have best success when mine are stored in my basement away from temp/hum changes.

I would aim for parallel faces. It really does make things easier for the turner. If you wanted to save yourself some work, then skip the bandsawing, and just knock off the corners with the chainsaw. As long as the bowl spins without a lot of sharp corners, it's pretty easy to take it into round on the lathe. But non-parallel faces can complicate the mounting. At the very least, make sure the mounting face is in the plane she wants it.

[Dale Gillaspy]

Ditto, but a lot also has to do with species. Some woods are more unstable than others and crack more, sealed or not.

[Dennis Ford]

Of the species you mentioned, I have the most trouble with Cherry. I have good luck storing logs for several months in the winter time but they go bad more quickly during the summer here. I don't like to store blanks more than a couple of weeks although it does happen sometimes (and a few crack as a result). If they are not getting turned the same day, I seal them with Anchor-Seal.

Most blanks I make are cut through the pith only, for really big bowls I will make another cut approximately parallel to reduce effort at the lathe. Orientation of at least one of those cuts is important to me, if neither one is right; putting the blank between centers can fix the problem but it is extra effort. The main issue with the cuts being sort of parallel (for me) is balance, if the balance is off much I have to turn the blank slowly at first.

[Jeff Grantham]

I've only just begun cutting my own blanks from logs myself, so I'm no expert. But so far I've had pretty good luck with respect to cracking and checking. If my logs are going to sit for awhile, I do seal them right away with Anchorseal. Also, I make sure that I leave an inch or 2 extra on each end so that if I get cracks at all, they're easily removed with a fresh cut. Mostly, if I get cracks on whole logs that have been sealed, it's from the pith, but usually they don't go more than a half inch deep or so.

And I hate to say it, but having relatively parallel cuts does make a difference. The first few I tried, I wasn't very precise, and found that it caused me grief on the bandsaw and also having it be out of balance. So I've resigned myself to actually taking the time to draw out straight, parallel lines on the logs before I make the cuts, to ensure they're pretty close. Much easier once they come inside for bandsaw and/or roughing work. i usually just use chalk and a square to draw my lines out.

[Reed Gray]

I have 2 video clips up on You Tube about using a chainsaw to prep bowl blanks. Depends on how serious your wife is about doing a lot of bowls. One is the Chainsaw Chopsaw. It makes cutting blanks with flat sides easy. The other is on free hand sawing, and I also have one on using a bandsaw. If you want dead accurate, than a bandsaw that cuts as high as the diameter of the bowl blanks is necessary, but the chainsaw chopsaw gets them pretty close. Type in robo hippy. There are several other good clips up on prepping bowl blanks. Having a sharp chain, and one that is sharpened the same on both sides helps keep the cuts straight. There is always some run out though because chainsaws are not 'precision' tools.

As for logs and cutting them up, I prefer to have whole logs and cut them up as I go. I loose less wood that way. If I cut a bunch of log sections up, even is sealed, they get checking on both ends. They should be covered, out of direct sun, and protected from the wind. Probably a good idea to have them off the ground. You can stand some pieces on end in the grass and cover them, and they spault fairly easily.

robo hippy

[Tom Davis]

Thanks for the comments everyone. I am disappointed that the wife is accurate about the need for parallel faces. I thought she was just being picky.

Prashun - I am storing the cut blanks in my workshop. The shop is not heated or air conditioned unless I am using it but it stays below 90 degrees and we have very infrequent freezes (this is south Georgia after all). Uncut logs are kept under a 24' X 10' lean-to off the back of my shop.

Reed - I have watched several of your videos (very informative) and recently built the chainsaw chopsaw. However, I set it up for my 20" bar and found that after attaching the guide bracket I need to use the 26" bar instead. I have not gotten around to drilling the other bar yet but will soon. My outside log storage lean-to is exposed on 3 sides but is partially blocked by nearby hedges and fencing. I may need to add some tarps to keep the logs from drying too fast.

[Matt Schrum]

When I have blanks waiting to be turned, I keep them covered in fresh shavings in my (unheated and un-air conditioned) shop. In mild weather they'll usually last a few weeks with minimal checking. I try not to let them go that long, but it happens depending on how long my Honey Do list is. Either way, keeping them out of the sun and wind while keeping them covered is your best bet.

[Brian McInturff]

A parellel face helps but isn't always needed. I turn a lot of blanks and just create the face I need on the lathe. Use a spur drive and start between centers and then adjust. A parellel face just makes it easier for her. Since its your better half then it's probably wise to try and accommodate her...lol

[Brice Rogers]

I've found that some wood will crack if you just look at it sideways - - like silver maple and white ash. I've also found that some are highly resistant to cracking.

Some of the things that I believe are true (based on reading, videos, and my own practical experience):
1. Coat the ends as soon after cutting the tree down - - don't even wait an hour or you'll see small cracks are starting. If you don't get there fast enough, then plan on sawing off a few inches of wood on each end. If you don't have the time when you pick up the wood, wrap the sawed up chunks in plastic (like a trash bag). That'll delay the cracking but if you wait too long, the logs will mold.
2. I have coated the ends with thick latex paint, paraffin, and anchor seal. I get paraffin for free (or next to it) at garage sales (old half-used candles). I apply it hot with a paint brush and sometimes "shoot" the coated surface with a heat gun. If you have a pot of melted wax, you can pour in paint thinner and stir it all up. That will make the paraffin into kind of a paste wax that can be used at room temperature. Gradually the thinner evaporates.
3. Removing the pith DOES help. Most cracking starts at the pitch.
4. Quick "processing of the chuck of wood into a bowl, vase or platter helps. Rule of thumb is the wall thickness should be about 10% of the diameter. I've seen (Wyomingwoodturner ?) that sealing the rough-turned bowl, etc. on all sides helps. I typically put it in a bag with wet shavings that I put into another bag. I've read that in dry climates that extra bags in a bag helps.
5. I saw on Cap't Eddie and other youtube videos that boiling helps. I've done that and those rough turned bowls did NOT crack. But it wasn't too scientific. I don't remember if the non-boiled chunks cracked. My biggest boiling pot is only 10 inches in diameter, so that is a limitation for me.
6. If you are rough turning and stop half way (dinner or end of the evening), wrap the half-finished piece with plastic or tin foil. It'll hold in the extra moisture.

YMMV....

[Scott Brandstetter]

Reed
Just watched your chainsaw chopsaw video. Where do you come up with this stuff. Amazing on so many levels. I am going to build this at some point. I don't know why anyone would do it differently. I'm glad no one has ever taken a video of my "method". Although, it would provide both humor and serve as a "what not to do" video. Thanks for the link and all the video's you provide.

I have 2 video clips up on You Tube about using a chainsaw to prep bowl blanks. Depends on how serious your wife is about doing a lot of bowls. One is the Chainsaw Chopsaw. It makes cutting blanks with flat sides easy. The other is on free hand sawing, and I also have one on using a bandsaw. If you want dead accurate, than a bandsaw that cuts as high as the diameter of the bowl blanks is necessary, but the chainsaw chopsaw gets them pretty close. Type in robo hippy. There are several other good clips up on prepping bowl blanks. Having a sharp chain, and one that is sharpened the same on both sides helps keep the cuts straight. There is always some run out though because chainsaws are not 'precision' tools.

As for logs and cutting them up, I prefer to have whole logs and cut them up as I go. I loose less wood that way. If I cut a bunch of log sections up, even is sealed, they get checking on both ends. They should be covered, out of direct sun, and protected from the wind. Probably a good idea to have them off the ground. You can stand some pieces on end in the grass and cover them, and they spault fairly easily.

robo hippy

[Thomas Canfield]

On larger tree sections, I like to remove a 15% D pith section or so. That pith section is quarter sawn material good for smaller bowls, saucers, spindle work, etc. Cutting a little extra will provide larger sections for small lidded boxes or end grain turnings. I do not worry too much about the parallel faces since I use a 3 1/8" D Forstner bit to provide a flat for a 3" faceplate on larger sections or else drill a 1"hole for 2 prong spur drive on smaller. I feel that I can level up the wood section and determine the center well enough than I am not worrying about changing orientation on lathe with faceplate. My Powermatic 3520 allows for handling the unbalanced blanks, and green wood usually cuts pretty fast. Rough turning the green wood as soon as possible after cutting the blanks is a big factor to prevent checking. Leaving a tree section complete log and then trimming back ends past checking will produce better blanks several weeks later will produce better blanks than cutting early and trying to seal ends if blanks are trimmed to close. The time of year trees are cut will also change, with fall and early winter much safer than spring and early summer.

[robert baccus]

I pile my log pieces together --apply a sprinkler immediately and every two weeks and ignore the piths. Then keep covered with a plastic tarp. When trimmed out to blanks they get endseal on all cut surfaces and are kept wet on the lathe with saran wrap or endseal. PS--I hate dry wood. The worst that can happen is great spalt. For long term(like after a hurricane) I store my wood in plastic barrels for years if necessary. $10 each. Emptied out a barrel today and found a walnut and camphor blank. Nice surprise.

[Dale Bonertz]

Lots of good ideas/advice given. The one question that really needs to be addressed is how long from the time of your processing to her turning them is there. If it happens within a week or two stack them on the floor in a contractor garbage bag. Once full tie the top of it and slide another over it. The blanks will get a little mold on them but not deep and will turn off easily. If you need longer term storage you will lose a lot with your method as you have figured out. Wrap the blanks in shrink wrap (cheap big rolls at SAMs Club) and put them in a freezer. They won't mold and will stay for years. You can purchase a cheap used chest freezer for this use, yes you need it running. If your blanks are more spindle turning blanks, say 3 inch by 3 inch and smaller ( length doesn't matter) then use a crock pot to heat wax. I just melt old candles or ? while I am prepping the blanks. Dip the ends of the blanks in the wax, it must sizzle when dipping or the wax is not hot enough yet. Stack these blanks on your shelf with space between. You can add rows to you stack as deep as you like. Once done turn the crock pot off and put the glass lid on. As the wax cools it seals the lid down waiting for the next time you need it.

It it is best to rough out bowl blanks as soon as you can if the above options are not viable. If roughing fairly quickly the contractor bags are the way to go and they are reusable for a long time.

Getting straight parallel cuts have more to do with proper saw maintenance and chain sharpening. Also make sure you are cutting down through the face grain side of the log not the end grain side.

Hope this helps,
Dale

[Reed Gray]

Scott, it is all my Dad's fault. He is an engineer, and though I am not one by training, I have the 'if it ain't broke, take it apart and fix it any way' syndrome. I would do some things differently, but the basic concept works. It does save time by letting just about any one make a straight cut. The run out I get comes from '1/16 off at the post makes for 1/4 to 1/2 inch off at the back end'. The angle iron comes in 10 foot lengths, and I would make the bed 5 feet long instead of 4. A 30 inch log section on that makes it difficult to cut the whole thing, though 24 works fine.

robo hippy