Oak signboaard cupping and splitting

[zool]

""Zool - yes, the sign is carved only on one side. The way it has cupped this is the outer radius of the cup. That's the reason I'm thinking of relieving the back by cutting a few slits (3mm wide by possibly 6mm deep) along the back face to relieve stress. There again I'm not sure if this would introduce a weakness along these lines as the timber expands due to weather conditions. If I do this I would still use the back braces - my thinking is that this would prevent it splitting along these lines.""

As the board is not a structural/weight carrying member, probably cutting reliefs in it will not cause weakness problem. Cuts that are 3- to 5-mm [0.10- to 0.25-inch] in a board "25mm thk x 200mm wide and 900mm long (grain running along the 900mm)" shouldn't be cause for concern.

The back braces will help, but as Louis indicated, make slots for the screws in the braces rather than holes so the screws will not be fixed in the braces and then split the braces.

I think that overall we are all suggesting to analyze the material you are using and anticipate movement, and take actions to minimize the adverse effects of that movement.


If all else fails, possibly pickle the sign in a good single malt. Maybe that will keep it calm for an extended period of time. If you don't want to use the single malt on the sign, then you and the sign's owner might sit down with the bottle. Soon the sign will not matter.

[Neil-R]

This is great help guys - thank you all very much for taking your time to help.

Zool: I like that final solution!!! The (scotch) whisky distillery, Glenmorangie single malt is no further than a mile from where I sit!!!!

I'm fine with all this now, but there's still one more issue that I need to make a decision on and that is what is the best finishing method. Danish oil gets a lot of good press and seems to be the modern preference (even for outdoor work). I've used this in the past in favour of varnish as it sinks in more and there is no flaking or bubbling over time when water may seep in. It's another dificult choice but right now I'm beginning to favour a good quality varnish. Perhaps there is another option?

[zool]

You might go see what is the best finish that is being used on boats these days.

Also: Look at this: Epoxy by the Leading Epoxy Manufacturer | WEST SYSTEM Epoxy

I do not know anyone who has ever found fault with any West System product [follow the instructions EXACTLY]. I live within 100 yards of salt water and there are 20 very large to small marinas within 5-miles.

Alas: No single malt distilleries [legal anyway] within many many many miles. Time for another visit to Galashiels.

[Neil-R]

OK Zool I'll look into that.

many thanks

[freecncplans]

Could you take the flatsawn boards and rip them to the thickness you want to use and glue them together? You want to orient the ripped boards to be 90 compared to the flatsawn board. I seen this in a wood working magazine once to get around buying expensive quartersawn boards.

Flatsawn board will shrink across the width and quartersawn will shrink in the thickness. I seen a 6 inch board fresh cut become 5 1/2" after going through a kiln. The quartersawn didn't have much of a change after the kiln.

Many of the antique furniture are made from quartersawn lumber and still around today going strong. This includes a table my Mom has that is a solid 5/4 18 inch wide piece of oak that has not split.

Sean

[louieatienza]

Could you take the flatsawn boards and rip them to the thickness you want to use and glue them together? You want to orient the ripped boards to be 90 compared to the flatsawn board. I seen this in a wood working magazine once to get around buying expensive quartersawn boards.

Flatsawn board will shrink across the width and quartersawn will shrink in the thickness. I seen a 6 inch board fresh cut become 5 1/2" after going through a kiln. The quartersawn didn't have much of a change after the kiln.

Many of the antique furniture are made from quartersawn lumber and still around today going strong. This includes a table my Mom has that is a solid 5/4 18 inch wide piece of oak that has not split.

Sean

The problem with the glue-up in an exterior environment is that you have to rely on the glue. i still thnk the best way would be, regardless of wood, to restrain it using mechanical means, yet still allow wood movement. No form of finish or tratment will permanently seal the wood from the elements. Especially a marine environment.