JH

John Hewitt

26/02/2004 4:59 PM

Qx2... Doors and finishes

Doors.
I plan to build a folding dry bar. The bar will have two doors at the
rear which open out to support the bar top. The doors are deep, about
ten cms. To have them close with a small gap, I shall have to taper
the two closing faces. I suspect that there's a "rule of thumb"
somewhere applied to double doors ?
How can I work out the taper to be applied?
Or, maybe there's another way?

Finishing.
When the bar is assembled there will be many places where access by
hand is difficult - maybe impossible. Pigeon hole type locations.
These places will be very difficult to apply stain and finishes. Is it
'practical' to apply the finishes before assembly?
If I do, how do I avoid damaging the finish when applying glue?
Is there an alternate method?
John Hewitt Malaga Spain


This topic has 2 replies

bR

[email protected] (Robert Bonomi)

in reply to John Hewitt on 26/02/2004 4:59 PM

27/02/2004 1:15 AM

In article <[email protected]>,
John Hewitt <[email protected]> wrote:
>Doors.
>I plan to build a folding dry bar. The bar will have two doors at the
>rear which open out to support the bar top. The doors are deep, about
>ten cms. To have them close with a small gap, I shall have to taper
>the two closing faces. I suspect that there's a "rule of thumb"
>somewhere applied to double doors ?
>How can I work out the taper to be applied?
>Or, maybe there's another way?

IF you can have the _back_ side of the doors flush with the front of
whatever they're mounted to, it becomes a non-issue. no need for any taper.

For the other extreme, where the _front_ of the door is flush with
the frame, then, the diagonal measure, from the front side of the door
at the hinge edge, to the back side of the door at the far edge, must
be no more than the width across the front of the door.

The easiest way to build this is to figure out how wide the back side
needs to be. The infamous Pythagorean Theorem gives us that answer.

square root of (door_width **2 - door thickness **2)

Example: if the door width is 60cm, with a thickness of 10 cm,
then sqrt( 60*60 - 10*10 ) = 59.16+

Thus, the taper needs to trim off 8.5 mm at the back of the
door, in order for it to close cleanly. Less than 8.5mm, and
the doors will bind; If it's more than 8.5mm, its only a
cosmetic issue -- people are more likely to notice that the edge
isn't 'square'.


>Finishing.
>When the bar is assembled there will be many places where access by
>hand is difficult - maybe impossible. Pigeon hole type locations.
>These places will be very difficult to apply stain and finishes. Is it
>'practical' to apply the finishes before assembly?

Not only practical, but probably a "GOOD IDEA(tm)" <grin>

>If I do, how do I avoid damaging the finish when applying glue?

(A) carefully mask off the areas where the glue _will_ be applied, while
doing the staining and other finishing -- you want to preserve the
'raw' wood surface for the glue to bind to in the joints.

(B) when ready to assemble, remove the masking from the glue surfaces,
AND MASK OFF the finished side of the pieces at the point of the join.

(C) use the glue _sparingly_. as in 'just enough to do the job'. this
minimizes the squeeze-out, and thus the need for any post-gluing
clean-up. do -lots- of practicing on some scrap stock. :)


FM

"Frank McVey"

in reply to John Hewitt on 26/02/2004 4:59 PM

26/02/2004 6:58 PM


"John Hewitt" <[email protected]> wrote in message
news:[email protected]...
> Doors.
> I plan to build a folding dry bar. The bar will have two doors at the
> rear which open out to support the bar top. The doors are deep, about
> ten cms. To have them close with a small gap, I shall have to taper
> the two closing faces. I suspect that there's a "rule of thumb"
> somewhere applied to double doors ?
> How can I work out the taper to be applied?
> Or, maybe there's another way?

Fit the doors so that they both fit closely when you drop them in. Then
hang the doors and close one of them. Close the other onto it - it won't
close since the diagonal of the door is greater than its width. Mark top
and bottom where it meets the closed door, and join the marks down the rear
of the meeting stile. Remove the door, joint the outer top corner to its
corresponding markon the inner top corner. Repeat for the lower corner, and
join the top and bottom inner marks down the length of the stile The you
can either take a bevel gauge and set it to the marks and use it to set up
your jointer fence (take very light cuts), or you can mount it in a vice and
hand-plane to the marks.

If you require the ability to open either door first, you'll have to repeat
the whole process with the other door.

>
> Finishing.
> When the bar is assembled there will be many places where access by
> hand is difficult - maybe impossible. Pigeon hole type locations.
> These places will be very difficult to apply stain and finishes. Is it
> 'practical' to apply the finishes before assembly?
> If I do, how do I avoid damaging the finish when applying glue?
> Is there an alternate method?
> John Hewitt Malaga Spain

It's quite common to have to prefinish some pieces before assembly, for the
reasons you describe. If you apply your finish then wax the components, the
glue will not stick to the waxed surfaces and will be easy to clean off when
dry. Don't use excessive glue, to avoid undue squeeze-out. Use a PVA
adhesive so that you can clean any excess with a damp cloth. You may have
to wrap it around a pointed stick if you can't get to it easily with your
hands.

It goes without saying that you need to keep your wax away from the
jointing surfaces (ie, those areas which need to be glued)


Cheers,

Frank


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