Government Cherry Wood Seal, Will it Warp?

[mjindustry]

We have a government agency wanting a 2ft. diameter wood carving. They requested Cherry Wood. We have never carved it before, does anyone have experience with it? We can get Cherry here that is about 1.5" thick. What about warping?

As an alternative we can make this in HDU, does anybody have some really good tips on faux wood finish over 3D hdu? I have done faux wood finish on flat surfaces but never 3D.


Thank you for any help! :)

-Melissa Jones

[blackhawk]

Melissa - I have carved a fair amount of cherry in 2D and 3D. It machines very well and holds good detail. I have the PC router and normally run at 19,000 rpm and from 2 to 3 IPS. I have not had any trouble with warping, but I am pretty careful with my lumber. I assume that this sign will be indoors, as cherry will not last long outdoors. I keep my shop between 40% - 50% relative humidity and I always try to move any lumber into the shop for at least 2 weeks before I am ready to cut it, 3-4 weeks are better. This lets the moisture content of the lumber reach equilibrium with the room. If the lumber warps after equalizing in the shop, you know not to use it. To further help the warping, I usually glue up the cherry in 3 to 4 inch widths. I use Titebond III and have never had a glue failure. I hope this helps.

[blackhawk]

A couple more things to note: When you do your glue up of the narrow boards, alternate your growth rings by looking at the end of the boards. This will help to prevent warping. If you need a final thickness of 1.5", I would glue up the individual pieces about an 1/8" over size. After you do the glue up, you will probably have some unevenness anyway. Just put the panel on the Bot and use a surfacing bit to clean up the 1st side, then flip it over and mill the 2nd side down to 1.5". This will make both sides dead flat and parallel.

[kevin]

Here how you buy it

4/4 = 13/16"
6/4 = 1-5/16"
8/4 = 1-13/16"
12/4 = 2-13/16"

If your not have a planer etc you wont be able to do it

Or get a cabinet shop to make the blank

Dont do the mistake i did using cherry outside

[mjindustry]

Thanks Guys! Appreciate the help very much!

The supplier of Cherry that has thicker stuff 8/4 is stored outside and we need to have this thing delivered in under two weeks. :eek:

I found some Cherry wood stored indoors but it is 1" thick (actually only 3/4")

Any ideas for the 1" Brad?

Or any ways to prevent warping with the 8/4 that is stored outside.

[srwtlc]

Stay away from the outside stuff, it's going to have too high of a moisture content and just be trouble.

Look for a reputable hardwood lumber supplier in your area or talk to some cabinet makers and find out where they get their lumber from. Maybe one of them would have some or could get you some with their next order.

I'm in the neighboring state (close to EauClaire, WI), UPS for a blank that size wouldn't be too bad. I can check with some of my suppliers. I don't have any 8/4 on hand at the moment.

If your carving isn't deeper than 3/4", you could face glue the 3/4" stuff and then edge glue after that, but it will leave layered and color/grain variance at the edges.

Scott

[blackhawk]

Like Scott said, you can face glue the 1" stock into 2" thick x 2 foot strips. Then run one side through the jointer and the 2nd side through the table saw. Then edge glue all the 2 foot strips together to get a 2'x2' blank.

The other possibility is to rip everything 1-5/8" wide and glue the whole blank together face to face to face, etc. This would be just like an edge grain butcher block. This type of glue up would be the most stable of anything. But as Scott mentioned for the first option, your color/grain variation could be even worse with this 2nd option.

[michael_schwartz]

Verify that the cherry has been dried to an acceptable MC for your area. In my region this would be to within 6%-8% Don't take "we dry it all to 6%" as an answer. Check with a moisture meter if you can, and allow the wood to acclimate your shop for a couple of days. If you can let it sit around for a few weeks.

You can eliminate most potential problems by selecting wood that has been dried properly.

If your panel is fairly stable to begin with it will warp to some degree but it shouldn't detract from the appearance. Make sure to follow the same finishing schedule on BOTH sides.

If you screw anything to the back for installation make sure to slot the screw holes. a 24" wide piece of cherry will expand approximately 3/16" with a change of 3% MC.

[mjindustry]

WOW! Amazingly helpful information here. Thank you to everyone!

I will report back the results asap. I think we may have enough knowledge to start seeking out the best supplier...

:)

-Melissa Jones
Nice Carvings

[ATX Poly Products]

I'm sorry I can't offer any advise on carving cherry as I have not done any...

But I read your write-up on the shopbot forum and visited your site. Congrats to you and all you've done!

Adam

[gc3]

We have carved a lot of hardwoods both exotic and US domestic. Found that by "face" not "edge" laminating to desired thickness and width helps control movement issues. Also seal bottom side before machining.

This from a guy in the desert in Mexico...

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

[cabnet636]

i have done quite a few of these in all types of wood, i can only add that in addition to correct glue up procedures that you do a back relief of say .2 to .25 leaving a boarder of 2 to 3 inches. "stress relief" and finish all sides. keep moisture content low ( on really thick carvings i look for 7 %


if you look at the wings of my 60" eagle (total was 72") the spring out a bit, some of this was from back carving a bit but most was due to the relief moving!

[bleeth]

Sometimes unintended consequences result in good things. The cup of the wings gives it a nice touch of reality.

[myxpykalix]

jim re:wings...if you had not told me, i would have thought you made it that way and think it looks cool, so sometimes its better to not say anything and let us think "man that guy has talent how the heck did he do that?"
good job:)

[cabnet636]

hang you fellows taught me what i know !! remeber robert cheals panel in show and tell # 9 and scot cox's "african mask" scanned by brady watson, those two post had the largest impact on me of all !!

[myxpykalix]

Melissa,
I can't back this up with factual data but it has been my experience since i've done alot of 3d carving that I usually never carve anything more then 1/3 the total thickness. So .25 deep on a .75 thickness board.
I have had things curl up like a bowl and you realize all that wasted effort and time.

Regarding finish, I think you would be better off using real cherry and staining that but regarding warping you'd be tter off using your preferred foam sign material but it would be a PITA to try to emulate a cherry finish.

Either way i'm sure you'll make it look fantastic.:D

[stump]

Melissa,

You may want to check out Renneberg Hardwoods. They have Cherry lumber on sale this month. One of the specials is:

CHERRY EDGE GLUED PANELS
19” - $12.00 ea 26” - $16.00 ea 28” - $18.00 ea
25/32” x 35-1/2” - In stock only

Don't know if the thickness would work for you, but the price seems right. They have a division in St. Cloud, not too far from you.

Also, to echo what else was said earlier, after reading the article and visiting your website, all I can say is Wow!

[wberminio]

Melissa

Since the issue is unequal moisture in the board,if the bottom /sides/edges are sealed/what if -after rough cutting/ top is sealed with a fast drying sealer-
like shellac-to seal the moisture . Then continue with finish carving
I did some thing similar turning wet (not dried) apple-wood bowls.I rough turned the outside and sealed the outside with wax before proceeding to turn the interior.
it kept the bowls from drying out too quickly and cracking.

[Gary Campbell]

Melissa...
One other item to be aware of. Many times the blank is glued up and not allowed to equalize. It takes a week to 10 days for a 2" thick glueup to lose the moisture introduced by gluing and get back to EMC.

For high end products we always take the moisture meter to the lumber store. There is no substitute for taking the time to do it right.

[cowboy1296]

In reference to a surface/planning bit. I work a lot with rough cut lumber. I have been using my table surfacer that came with my buddy which leaves tooling marks while planning the board. Is there a better bit for planning that can do a better job?

Another question that does not relate to this thread but i like working with beetle kill pine. some larger stock boards that i have bought are full of worm holes, enough to booger up a rustic sign. other then wood filler is there some other way to fill these holes (such as glue with saw dust) that works well that is weather resistant. If you are not familiar with beetle kill pine i am going to post a picture soon of a sign being made. This problem was brought on by the supplier rather then the wood/beetles.

[COBOB]

Hey Rick, I haven't had the pleasure of working on any beetle kill pine on the CNC, too new. I have turned some on the lathe and have used 2 methods. Titebond and sawdust works well. I like the effect of coffee grounds packed in the holes and superglue soaked into it. I think it looks neat.
Try it, you will like it.

[Gary Campbell]

Rick...
Can your tool marks be described as ridges that form parallel to the direction of travel in that area?

If this is the case, take some time and plumb or tram the spindle to get it perpendicular with the table. If the ridges are in the x direction, then the spindle needs to be tilted left or right when looking at the "front" of the spindle from the X=0 end. If they are present with the Y travel, you will have to either shim the spindle mount plate to the Z extrusion or loosen the bolts that hold the Y extrusions to the side plates. There are a number of informative posts here on the forum, if you search for them. Also there is more info here: http://www.shopbotblog.com/index.php/2008/12/tuning-up-the-prs-gantry/

I have had good luck using an insert surfacing bit: http://www.toolstoday.com/p-5785-spoilboard-surfacing-insert-cutter-router-bit.aspx Works great on lumber also.

For an exterior filler I use Bondo or a clone. Get the ones with the red hardener and tint with powedered concrete dye. Doesnt wok well with light colored fills, but its weatherproof and cures as fast as you want it to. Takes stains and most finishes.

[mjindustry]

Purchase order received this morning on this project! :)

They decided to have me make one in HDU, and one in Cherry! :eek:

Wish me luck. I have taken every post into consideration and appreciate them all very much! (more on that later)

[michael_schwartz]

I think it will turn out nicely. I would use solid wood for a project like that in a heartbeat.

[Gary Campbell]

Melissa...
Congrats on the commission. Keep us informed of the progress and dont hesitate to ask any quesions you may have on the Cherry. After seening your work, you have the HDU well in hand.

[jerry_stanek]

Rember Cherry darkens with age.