Black walnut or hardwood questions

[cowboy1296]

I started out with a true 2 inch thick piece of black walnut which i planned fairly flat. the black walnut was suppose to be dry and my depth of cut was 1 to 1.1 into the wood. almost over night the board started to warp. my thicker pieces that i have worked with in the past did not. I was told by someone locally that perhaps cutting slots on the back of the board could possibly take of the warping.

Anyone want to comment on how i can prevent the board from warping after cut. i do like working with black walnut and am about to venture into elm.

this is still a work in progress and i should be able to take the grainy-ness out of the project.

[srwtlc]

Rick,

When you take material off one side, you're relieving stress and exposing that surface to humidity changes, thus the cupping. You can cut a shallow relief pocket in the back side if the project permits. If the blank is of one solid piece of wood (not glued up narrower strips), it's almost inevitable that it's going to happen. The wider and thicker the piece along with the depth of cut, the more likely and pronounced it can be.

If you glue up a blank from 2" - 4" strips, try flipping every other board (heartwood/sapwood side up) while still maintaining a favorable grain/color match. That way, each boards movement will attempt to cancel out the other.

The other option, although not always available and more costly, is to try using quartersawn or riftsawn lumber.

While kerfing the back of the piece (with a tablesaw) may help, it may not be desirable to have kerf cuts showing on the edge of the piece. This is more often done on the back of a slab type cabinet door when a V-groove or bead is cut on the front of a panel. Cleats are generally added to the back then.

Scott

[cowboy1296]

i have been resisting getting a biscuit joiner but i do like working with hardwood.

i am about to have the opportunity to invest in as much black walnut and elm rough cut lumber as i want or can afford.

now correct me if i am wrong. but if i have a 2 inch thick piece that could be as wide as 18 inches then i should cut it into 2x4's and flip flop every other board and join them back together? does that make sense?

Sorry for being dense, I am still working on my first cup.

I did cut the Marine logo into MDF, man what a lot of machine time. I did chip out a few small pieces but after staining it, it is not noticeable.

thanks again

[mark_stief]

I never glue up anything wider than 3" when making panels and don't worry about the biscut joiner all I use is titebond III the last thing you need is a biscut showing up in you're carving

[cowboy1296]

I can buy a lot of glue for what buiscuit joiners cost.

[cowboy1296]

I am picking up 3 bar clamps tomorrow, thanks for the advise.

[waynelocke]

I would not cut an 18" wide board into 4" sections and glue it to prevent warping. If you flip a board every 3 or 4 inches the color and grain will not match. Most woodworkers I know match boards for glue up based on grain and color match.

If you have to do that then there is probably a problem with the board or the process. As mentioned above you need to remove equal amounts of material off of both sides of the board. If using a planer the board is usually flipped after every pass.

When someone tells you that the material is dry, what do they mean? They should be able to tell you and show you the moisture content which should be around 8% or 10% depending to some extent on where you are. A moisture meter is a good investment if you are going to work with hardwoods.

Also, how the wood is cut and where it was in the log can also affect the warping.

[myxpykalix]

Rick,
I have had the same issue with thick walnut and other woods however not that thick.

If you have a 2" thick piece and are carving out one inch leaving at least a 1" thick base it shouldn't cup.

Here are a couple untried ideas.

if you want to start with a 2" thick piece then why not take 2 one inch thick pieces and laminate them together (maybe cross grain?) then adjust your Z height of your model so as not to go lower then your top 1" then you have a solid uncut one inch base to keep the top from cupping.

Maybe someone can comment on the advisability of gluing cross grain, or just glue the 2 pieces regularly. The point is you have a sturdy "base" that is not subject to the forces of stress caused by the removal of all that material and the top layer because it is cut alot, if cut before it is laminated would cup severely but because it has the glue holding it to the base would not cup.

Another idea would be to simply adjust your Z height through experimentation to a point where it won't cause the cupping. Can you post some pictures of what you have now?

I would bet you could adjust your Z height at least .25 without a deterioration to quality.

[Gary Campbell]

Rick...
Along with what is mentioned above, I would add that you need to check the moisture content of the wood. Never, I mean NEVER, trust that an air dried piece of lumber is at a machinable moisture content (MC). Very seldom trust a kiln dried piece that has been stored in an area where the relative humidity is above 25%.

Every piece that I have machined at over 10% MC has curled, almost every one over 8%.

There are a good number of MC articles on the woodworkers forums that can help you gain insight into MC stability.

[cowboy1296]

the elk scene in the first post on here is what i cut. you cant tell from the picture about the warping. with a wall hanger the warping my not show that much.

i did two different elk plaques. the first and largest warped a lot and i broke the board trying to bend it, but it is not totally destroyed. one other black walnut plaque that i did was only v carved and i have been told by the vet group that i donated it to that it did not warp at all. it was about 17x32x2 so apparently its all of the cutting that i am doing.

its funny that you mentioned gluing. i did find a 1x11x40 inch scrap piece of black walnut. cut it half and glued it together matching the grain. and did a 3 d cut that went about half way in and i just checked it and its still flat but it is not nearly as big as the others being 10x18x1.6. its a work in progress and i still have a lot of burr removal to do. but you might be right about gluing.

here is a picture of the elk scene that warped. i reduced the quality too much but you can get the idea. the marine plaque is still flat

[Gary Campbell]

Rick...
Have you checked the MC of any of these pieces before or after cutting?

[cowboy1296]

that would mean i know what i am doing. to answer your question no i have not and do not even own a moisture meter. but i was pricing them. i am nothing more then a hobby here so what is a good entry level moisture meter on the market. here is one that i am looking at by general tools, reviews are good but i know nothing about moisture meters.
http://www.amazon.com/General-Tools-MMD4E-Digital-Moisture/dp/B00275F5O2/ref=cm_cr_pr_product_top

perhaps its a good way to go with me buying some black walnut and elm hopefully in the near future. the logs have been down for some time but have yet to be milled. but living in colorado the humidity here right now is 16 percent outside.

[myxpykalix]

I do recall that a plaque i did in walnut (similar depth as your elk plaque here) curled and it was done in 15 year old air dried wood. One thing i did that helped it was i took it to my basement and laid a 50 lb sandbag on it for a month or so with the crown of the curl up.

[gc3]

http://www.woodweb.com/knowledge_base/Woodworking_101_The_Basics.html

http://www.woodweb.com/knowledge_base/A_Finish_Carpenters_Guide_to_Understanding.html

[wberminio]

You're going to have issues with thick solid wood whether solid or air dried.
MC is important.It is difficult to dry the center of thick boards.
As you cut away into a carving,an imbalance is created in the board.
One solution is to use quartersawn lumber.IT is a bit more stable than plain sliced .Even though it may be difficult to get in larger widths,when edge glued the glue line may not be as noticeable.
The beauty of wood is what makes it stressful at times..;)

[dauteuil]

Quarter sawn is always better.
But if you glue-up a board for whatever reason, you should always let the glue dry with both faces of the board exposed to air.
Meaning: Don't lay the board flat on a bench or table while the glue dries.
Stand the board on it's edges against something or leave it in the clamps standing up.
Years of experience as a woodworker and hundreds of board glue-ups later,
I now know that the moisture content of the glue is enough to make the board warp if the extra moisture is allowed to escape from only one side of the board.
Of course as others have pointed out, the overall moisture content of the wood has to be below 10% to start with. I prefer kiln dried at 6%.
Then again some pieces of wood have stress forces in them that are released when you start carving into it. Not much you can do about that.

[cowboy1296]

well lets hope i have learned from yalls advise since i just bought 100 board feet of black walnut. i expect it to be high in moisture content for now but it looks good. i also am the proud owner of a moisture meter but have not even plugged in the battery yet.

second that I just checked it and its 18 percent but it should dry fast since the humidity level here now is 1 percent.

[cowboy1296]

I just bought a good looking piece of teak. its a tad under 9 inches wide and 90 inches long, 1 1/2 inch thick. the moisture content is right at 5%.

i plan on cutting the board into thirds and glue it together. now should i add an extra step and rip this 9 inch wide board first and then glue it back together or is teak suitable at nearly 9 inches wide?

the plaque will be mostly v-carved but will have a 3d bowl image in it 10 inches in diameter

you guys seem very knowledgeable is why i came back to you for help.

[bleeth]

Teak doesn't cup as readily as many other woods after it is dried and surfaced. If you hold to no more than 1/3 the thicknes in depth I don't think you will have an issue. That being said there is never a guarentee!
For your gluing TB2 will work fine but wipe the edges to be glued down with acetone first to leech the surface oil out.

[cowboy1296]

here is the artwork of what i want to cut. the real dept cut is a army logo ten inches round and maybe a half inch deep. the rest of it vcarve. thanks for the tip on the acetone. now question about acetone, should i use it on any and all boards being glued or just the teak?

[bleeth]

It's not needed for most woods. Teak is fairly unique due to the high amount of oil in it.

[Gary Campbell]

Rick....
Along with the high oil content in Teak, there is also a high silica content that will tear up cutting tools. Make sure you have extras on hand.

[cowboy1296]

Tears up tools. This may be my only experience with teak. I am taking a long vacation in September so this will give me the opportunity to get all of my bits sharpened.

Thanks for the tidbit about the acetone. You see I would have never known that. You guys have definitely been my think tank

[cowboy1296]

First off i took the teak back to the candy store and traded it in.

I am still using thicker stock, 1.7-1.9 inch, of black walnut and alder. These are kiln dried but i have had problems in the past with kiln dried as well. What i have found that greatly reduces the warping by 85-95%. I leave the plaque secured inside of the pllank by tabs and the whole plank clamped down on the bot for 48 hours. Not sure how much time is actually necessary it is just the amount of time i chose. Repeatedly i have noticed little or no warping.

Not that you experts need an explantion and you are welcome to edit this. But cutting a 3d plaque into any board the insides will be more moist then out. by leaving it clamped down allows the inside to catch up with the outside and the clamps prevent it from moving. FYI living in high altitude my humidity level here is almost always low. Anyhow over a few day period and constantly checking the warping, it is much improved.

[cowboy1296]

Question: my last pieces of black walnut have sucked and not really sure if there is better to be had her locally. I do like working with black walnut, but if i can not get it what wood would you suggest. I am able to get cherry but need a substitute for black walnut. If you have pictures of 3d carving in your choice of wood would be nice as well.

[bleeth]

Rick:

Check these guys out:
http://www.gobywalnut.com/

Although I don't think it is original owner they were the go-to guys for it for years.
They ship all over.

[cowboy1296]

i have bought from out of state vendors before and although the wood is great the shipping kills me. The beauty of my suppliers is that he is a furniture maker here locally and he has a supplier deliver on a regular bases. I cant beat the price but the supply has gotten bad. Plus i have done some work for the furniture maker. Thanks for the link

[bobmoore]

Cowboy you aren't giving any prices so I am not sure what you are paying for walnut. Around here we pay $3-4 for decent walnut. Much more for burled or figured. 2 things to try;
1. African mahogany can be a substitute although it doesn't run any better you may be able to find it in the same price range (it costs more here than walnut but check your supplier).
2 From the looks of what you are posting for projects you may get a better deal by buying shorts and have them ups or fedxed in for freight savings.
Bob

[kurt_rose]

Here are a couple of wide pieces I've done. 1 is cedar and 26" wide the other black walnut is 20" wide. I think both started at 2.25" and i left 1" thickness after the carving. They were 12% MC. and both air dried and have experienced no cupping what so ever. Going to be doing a lot more of this stuff for door panels so I'll have to go a lot thinner (Probably .5), but I think putting them into a frame will go a long way to keeping them flat. I just bought a bandsaw mill and am getting ready to build a solar kiln to speed drying and getting that MC down as low at possiable. Like most have said MC is probably the most important factor.

[cowboy1296]

I have some african mahogany in stock but i am not sure that i care for it as much. i think open grain is the issue.

Up until now i have stayed away from soft woods for 3-d. That cedar carving is beautiful. did you have a lot of fuzzies?

[scottp55]

I've got some 2.125" thick Claro Walnut slab I was going to do some .5" deep 3D's in.
About 16" wide.
It was kiln dried, but has been acclimating in house 18 years.
Based on experience, do I need to worry about warping?
Would some 1" thick Hard Maple inlays help(or even be necessary)?
scott

[kurt_rose]

I think you'll be fine Scott. I like to leave at least an inch backer so you could go even thicker on the model if you so wished.

[kurt_rose]

That cedar carving is beautiful. did you have a lot of fuzzies?

It was too bad Cowboy. After the first coat of sanding sealer it was fairly easy to clean up. The good thing about cedar it that it dries fast. I cut this tree down about 6 months before carving.

[cowboy1296]

i always leave an inch backer as well. its just a number i picked out of the air so no rhyme or reason to it. my gut tells me it will warp. no matter how dry the outside of the wood is the inside will always be more moist. so when you cut into that moist you will see a reaction. but who am i, i am still learning about wood and am always surprised about movement or lack there of. But man that is a pretty piece of black walnut.

[scottp55]

Thanks Kurt,
I've been using a gut figure of no more than 50% thickness cut, but no experience yet except .25" Bloodwood buttons.
Yeah Rick, That's the only short I have...You should see the 14 footer that matches it:)
Planed max thickness and came out 2.2" and it goes from 17" down to 15.5".
Claro is quite often that good that I've seen here..Nature of the wood.

Maybe find out when your supplier is getting a big shipment in, and BE there to cherrypick as it goes in the racks....bring your denatured and a rag:)
scott

[cowboy1296]

My shop is the corner of my garage, so not more room for toys. I use the furniture maker to make planks for me. He knows what i need and he is convenient. His supplier is 100 miles away, one way. He is making a run this next week to look over their inventory.

[srwtlc]

Scott, that slab you have there is going to look horrible! You best send it to me so I can properly dispose of it in my lumber rack and save you much grief! ;)

[cowboy1296]

now you see how you are, actually i wish had thought about that charitable act first.

Now i have to go to work. I have made a few cutting boards for everyone except me, so this is my gift from me to me. I have some black walnut that is not suitable for my plaques, but it should do well with the cutting board. It will have two sides, one to use and the other to show. this is the show side.http://www.talkshopbot.com/forum/attachment.php?attachmentid=27570&stc=1

[scottp55]

Yeah Scott, You're right...it's so ugly I'll use the bottom third to make a city street out of it (Sans the flourish frame).:)
Maybe the Really ugly top part for a bear scene with almost no detail in it.
Keep dreaming. :)
scott

[cowboy1296]

and here i thought that it was a genuine act of kindness. i did this one out of the same walnut that i am cutting the cutting board out of.http://www.talkshopbot.com/forum/attachment.php?attachmentid=27573&stc=1