Hatch question

[dewayne]

Should the top cross spar on the hatch also be oak for the other part of hinge to be screwed to also? All my other spars on the hatch will probably made from 2 pieces of 3/8 arauck (spell) ply laminated together witch will make each piece approximatly 7/8".
All suggestions appreciated.

dewayne

[Juneaudave]

Maybe this thread will help...

http://www.tnttt.com/viewtopic.php?t=3131&highlight=hatch+spar

[rbeemer]

Dewayne,
I think it depends on what side of the spar you are screwing into. If into the top of the plywood(side where you can only see one layer of wood) you should be okay. If you are screwing into the sides(where you can see the layers of the plywood) then there is a bigger chance for failure in having the screws pull out/loosen and I would use a piece of solid hardwood.

Remember there is more stress on these to spars than any other when you are opening and closing the hatch and the reason folks use oak(the world according to Rick) is that oak tends to not flex as much as any other and for it screw holding capabilities. You can use other hardwoods but I do no think you will finds a species as cheap as oak(again just Rick's opinion)

[dewayne]

Thanks juneadave, I'm gluing as well as screwing so I will use oak for my 2 spars for the hatch hinge.

dewayne

[halfdome, Danny]

Red Oak is OK, White Oak is better but I used Eastern Rock Maple for both spars that hold the hurricane hinge and cabin door hinges.
Danny

[Gerdo]

I also used Maple for anything of concern.

[Ira]

Spars for the hatch?

Heck, you can use pine.

[asianflava]

Spars for the hatch?

Heck, you can use pine.

I used 3/4in ply for my spars.

[halfdome, Danny]

Spars for the hatch?

Heck, you can use pine.

I have as much use for pine for hinges as I do a cow pissin' on a flat rock. Danny

[seahorse]

Oak or maple........both are hard wood , and will hold screws well.

[Ira]

Spars for the hatch?

Heck, you can use pine.

I have as much use for pine for hinges as I do a cow pissin' on a flat rock. Danny

IT'S A STUPID HATCH, FOR GOD'S SAKE!

WE'RE NOT BUILDING THE SPACE SHUTTLE HERE!

And I don't understand that metahphor at all.

[halfdome, Danny]

Spars for the hatch?

Heck, you can use pine.

I have as much use for pine for hinges as I do a cow pissin' on a flat rock. Danny

IT'S A STUPID HATCH, FOR GOD'S SAKE!

WE'RE NOT BUILDING THE SPACE SHUTTLE HERE!

And I don't understand that metahphor at all.

Ira, Pine, Yellow is a soft weak wood in all strength properties with a specific gravity of .39
Red Oak has a medium bending strength and stiffness with high crushing strength with a specific gravity of .77
White Oak is the same with a specific gravity of .76
Rock Maple is high in all strength properties except stiffness which is medium with a specific gravity of .72
My reference is from "World Woods in Color" by William A. Lincoln
Specific gravity is a measurement of density of wood. Exceptionally light is .30 or less. Light is .30 - .45, Medium is .45 - .65, Heavy is .65 - .80, Very heavy is .80 - 1.0, & Exceptionally heavy (won't float in water ) 1.00
A cow pissin' on a flat rock will get you all wet if your standing close and most don't desire that. My garage man door is framed in fir, Douglas ( second or third growth ) with a specific gravity of .53 and the screws come loose more often than I desire. Danny

[len19070]

Spars for the hatch?

Heck, you can use pine.

Not to say anyones wrong or right.
But I use 5/4 yellow Pine for the hatch spar and the rest of the spars as well. That rear spar, no matter what its made of should be part of a larger convergence of several pieces of wood/plywood forming a beam. Once the roof sheathing, rear bulkhead plywood the interior cabinet and side walls are glued/screwed to it. Providing the hinge is done correctly and doesn't leak, Its never going to move-split or let 11 or 12, 1 1/2" screws come out.

Happy Trails

Len

[Ira]

Spars for the hatch?

Heck, you can use pine.

Not to say anyones wrong or right.

Yes you did.

[halfdome, Danny]

Spars for the hatch?

Heck, you can use pine.

Not to say anyones wrong or right.
But I use 5/4 yellow Pine for the hatch spar and the rest of the spars as well. That rear spar, no matter what its made of should be part of a larger convergence of several pieces of wood/plywood forming a beam. Once the roof sheathing, rear bulkhead plywood the interior cabinet and side walls are glued/screwed to it. Providing the hinge is done correctly and doesn't leak, Its never going to move-split or let 11 or 12, 1 1/2" screws come out.

Happy Trails

Len

For the few dollars you save and I spend I have a stronger insurance policy that all that hard work will last. Old growth pine is one thing but the stuff available today doesn't have the strength properties. The only time I ever use pine is when a customer specifies it for decorative purposes. Danny