Wood workers and sign makers, Help Please!

[GrammaPam]

Looking for ideas on what is causing and how to solve (or prevent on future sign) wood cracking problem.

My daughter had a friend that needed a sign, you know how it goes: "Oh, my mom/dad can do that for you!"

My first advice to them was to use a local sign maker that would also install it professionally. No, they really wanted me to do it, 4 1/2' X 4' and carved on both sides.

I started with 2" hemlock and planed it down to 1 inch; carved both sides of each board; biscuit joined and glued the boards; glued and screwed a 2” edge on all sides, front and back. My theory was the longer top and bottom edge would act as a brace. They extended out to reach the 6' posts and would allow the wind to pass around and offer some flexibility. The paint is latex based enamel except for the gold detail.

The original sign is seen in photo one with the proud wine master. Photo two shows the new, closer posts with the sign mounted directly on them, braces removed. If you zoom in real close you may be able to see some cracks on the top right corner in the gold border of the logo and from the left edge through the words “Tasting” near the bottom. This started within two months. A couple weeks ago a new crack appeared as shown in photo three. The cracks appear suddenly and go clear through the board, enough to see light through to the other side.

The only other possible contributing factor may be that the sign resides about 400 miles from where it was made. I was very proud of this sign and am not at all happy with the way it is cracking. Someone out there is going to have a suggestion. This cannot be a singular problem. Any thoughts would be welcomed.

Thank you in advance.
Gramma Pam

[Sallen1215]

My first question would be what type and quality finish/sanding sealer you used? If you just painted over raw wood then the cracking can be from tangential wood movement from its natural desire to pull in moisture. When i have to make an outdoor sign i either use azek pvc board or I used cedar, both of which i have had good results with. Raw wood with just paint in it wont stand up to the elements as the pores in the wood are still able to move and swell. Thats just one idiots opinion..

Stephen

[AskBud]

Looking for ideas on what is causing and how to solve (or prevent on future sign) wood cracking problem.

My daughter had a friend that needed a sign, you know how it goes: "Oh, my mom/dad can do that for you!"

My first advice to them was to use a local sign maker that would also install it professionally. No, they really wanted me to do it, 4 1/2' X 4' and carved on both sides.

I started with 2" hemlock and planed it down to 1 inch; carved both sides of each board; biscuit joined and glued the boards; glued and screwed a 2” edge on all sides, front and back. My theory was the longer top and bottom edge would act as a brace. They extended out to reach the 6' posts and would allow the wind to pass around and offer some flexibility. The paint is latex based enamel except for the gold detail.

The original sign is seen in photo one with the proud wine master. Photo two shows the new, closer posts with the sign mounted directly on them, braces removed. If you zoom in real close you may be able to see some cracks on the top right corner in the gold border of the logo and from the left edge through the words “Tasting” near the bottom. This started within two months. A couple weeks ago a new crack appeared as shown in photo three. The cracks appear suddenly and go clear through the board, enough to see light through to the other side.

The only other possible contributing factor may be that the sign resides about 400 miles from where it was made. I was very proud of this sign and am not at all happy with the way it is cracking. Someone out there is going to have a suggestion. This cannot be a singular problem. Any thoughts would be welcomed.

Thank you in advance.
Gramma Pam

My first guess is that the cracks are not on the joined edges, but within specific boards. However, the cracks could still be due the pressure of the biscuits and glue. Expansion is a funny thing. Many sign makers use a special "Sign stock" rather than raw wood. I've even seen some that allow each panel to "float" within the frame. This allows for the boards to nest on each other but not bind.
AskBud

[jaroot]

Way over my head! I haven't had any of my outdoor signs crack yet but warp and peel definately. I think I know what has been causing those things but not sure what to say about you big sign

[DaveN]

My guess would be that the wood is dring out. You went from a 2" thick board to 1" thick and then carved even deeper into center. The center of the board is going to have more moisture then the outside. To fix it I would fill the cracks with bondo and repaint it.

[GrammaPam]

Stephen, planed and sanded well, undercoated with outdoor Kilz. Only reason for using the hemlock was to still be a bit thick once it was carved. Good ideas.
Bud, you are right, cracks are not at edges of boards. The float idea was a thought due to the concept of a panel door and hardwood floors. Thanks for your always insightful input.
Jaroot, this is the first sign I've had crack, though a thinner one did warp. This was my largest one so far.
Dave, thanks for the thoughts. Your avitar looks like the work of a gifted wood worker.
Appreciate the ideas everyone.
G.P.

[Digitalwoodshop]

What was the source of the boards? I am thinking it was still too wet....

I too would have made the field of boards out of PVC and use Wood Biscuits in the long pieces and NO Glue. The boards would float in a frame one on top of each other. Make the decorations of PVC and only glue it to one plank if possible... The reason for the biscuits is to keep the boards flat. You could even use your CW and cut some Engravers Plastic or the Fiber Re Enforced Plastic into Biscuits to keep from having wood problems.

My adventure in PVC Signs, the KUHN Alpaca cut out letter have yet to be installed.... so I don't know how they are going to fare...

It could have simply been the side hardware.... metal un giving in the field of the boards.... A U Channel on each side would leave the boards free floating... That would have been my method.

Good Luck,

AL

[b.sumner47]

I would think it has to due with moisture. How long were the boards dried, natural,or kiln ? Did you notice if the ends were sealed or not, could tell how the boards were dried middle out. When I join wood for outdoor sign, I first bisquit the wood and use waterproof glue and on the backside I use wooden strips of 1in by 4in depending on the size of the sign, glued and screwed, oposite the grain on the front side. No complaints yet. Capt Barry

[Ike]

Crud try this again I had a post and lost it! Okay I am throw in my 2 cents worth of my 30 years of sign making experience! This is what I do and by no means the only way to do it! I stopped using dowels and never used biscuits for a few reasons. One with dowels if you drill too deep and hit it when carving it leaves a void. Two if you hit the dowel or biscuit they are exposed and weakens them defeating the purpose! But the main reason I stop using dowels is Gorilla glue! With Gorilla glue there is no reason to use dowels, because it works so well the board will break before the joint will break. What I do is wet both edges of the board and apply a thin coat of glue on one side. Too much is bad since the glue will expand.

Also I try to use smaller boards to avoid warping, for example if I am making a 2 foot by 4 foot sign I will use 4- 6" boards rather then 2- 12" boards. One you rarely find a true 12" board and using the 6" board you will get a true 24" wide sign and lessen the chances of warping.

To help in cracking the ends grains must be well sealed. There are end grain sealers on the market you can use or you can use wood glue diluted with water or silicone. But the best method I have found is 4 coats of exterior paint ( I use water based) allowing each coat to dry. Then I apply 3 coats of polyurethane along with finishing the face. Plus the material you use does make a difference. I use redwood on all my signs and for double sided signs I use 2" stock and kiln dried is the best, but will still crack. I use a moisture meter to check my material and ideally you want 15% at the most and preferably 6-7 %. Plus how is it cut is important, flat sawn meaning the end grain will run horizontal is more prone to warp when wet and is drying the wood shrinks. Vertical grain or quarter sawn lumber will have vertical grain and will tend to crack when drying and shrinking. Vertical when dry is the strongest.

Another thing when you enclosed the sign in a frame did you allow for expansion and contraction? In the winter if the end grain is not well sealed it will hold moisture and contract and in the summer will expand. If the frame is tight then the sign has no room to expand it will begin to warp and crack. I bet if you look on the end the sign is warping some? So when using a frame allow about 1/4" on each end. Another thing I have done when using 2" stock is using an 1/8" 1.5" metal flat bar on each end. I drill holes and counter sink them, drilling the holes so that they are in the middle of each board glued.

You say you used hemlock, it is a good framing material and is prone to crack from nails and screws. I am not sure it is a very good material for signs? Plus if it was high in moisture content and you planed it down from 2" to 1" it sped up the drying process and increased the cause of cracking. It also reduced the strength and carving even more. Was the material rough cut? I would choose a more suitable exterior material such as redwood, cedar, cypress and even sign board if like your sign completely painted. But with any lumber even kiln dried check the moisture content and how it was cut vertical or flat sawn. Heart wood is always good also! Then seal the end grain well and of the face too! Then if you frame the sign give it some breathing room!

Well I hope I helped? Here is a great resource on moisture of lumber http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr117.pdf. As I said before these methods are what I do in making signs and by no means are the only way!

Ike

PS if I have repeated other members, I apologize I didn't read every post!!!

[www.carvenow.com]

For big sign like this. I would rather cut out the text and everything separately then glue it on a big plywood board. Would make thing easier.
Great sign by the way.