Methods for Attaching Moldings

[Ford Fitzkee]

    I was hoping to get some input on people's techniques for attaching moldings to cases.  My current method seems to be working OK, but I think there has to be a better method out there.  The basic method I use is to attach the front molding first, marking the miter locations directly from the case.  Then I fit the returns, sawing them flush with the back of the case after they are attached. 
    The issue I had with the front molding pictured below was clamping it.  I decided to clamp it at the the only place I could, which was the bottom fillet.  This caused a very slight gap where it meets the case as seen in the photo.  The only way I can see avoiding this issue would be to nail it in place with cut headless brads when I glue it or to use a rub joint with hot hide glue, avoiding the need to clamp altogether.  Has anyone had success with using rub joints on moldings?
    The other thing I am debating is wether I can omit nailing the front portion of the molding since the molding is glued long grain to the case bottom.  I will definitely nail the returns on the sides of the case to help deal with the cross grain construction.  Was it typical for period pieces to omit nails on the front molding?

 

[Jack Plane]

Cut pins (or fine headless nails) were commonly used for attaching mouldings. I rub the mouldings on first and then anchor them with pins to prevent them sliding around while I affix the others.

 

[zdillinger]

I also glue then pin with headless brads.

 

[Ford Fitzkee]

Do you think that ommiting nails on the front molding and relying only on glue is asking for trouble?  Most period pieces I have seen use pins, however, I have seen some pieces where I can't find any signs of pins being used on the front molding.

I'll try rubbing the molding on next time.

-Ford

 

[Jack Plane]

Not asking for trouble per se: If you position the front moulding accurately and let the glue set sufficiently, you shouldn't encounter any problems when attaching the return mouldings.

 

[Ford Fitzkee]

    Just did the return moldings using a rub joint and hot hide glue.  I haven't done too many rub joints and was a little nervous but it worked great.  No gaps caused by distortion from clamps like the front molding.  It tacked quickly and I was actually able to position the molding much easier than when using clamps.  I am going to omit the nails on the front molding and only nail the returns, we'll see how it works out.
    Jack, I have noticed on your blog posts that you use rub joints with hide glue for almost everything.  I may start using rub joints more often.     

-Ford

 

[Jack Plane]

Yes, rubbed joints answer the majority of my needs, however, mouldings formed on the edge of a board can sometimes take on a twist or bow when sawn off the parent board, so nails offer the ability to fine tune the position of the mouldings which glue alone cannot achieve.

Nailing mouldings is virtually essential if one wants to attach them all at once, otherwise adjacent mouldings simply move around on the glue when trying to match the mitres. I pre-nail the mouldings (drive the nails through the mouldings to knock out the 'break through' that would inevitably prevent the moulding from sitting flat – and then knock the points flush with the glue face again) so that a couple of taps with a hammer will secure them without disturbing the glue's bond.

 

[pampine]

...Nailing mouldings is virtually essential if one wants to attach them all at once, otherwise adjacent mouldings simply move around on the glue when trying to match the mitres. I pre-nail the mouldings (drive the nails through the mouldings to knock out the 'break through' that would inevitably prevent the moulding from sitting flat – and then knock the points flush with the glue face again) so that a couple of taps with a hammer will secure them without disturbing the glue's bond.

Jack, I don't understand the last sentence of your advice. What does "drive the nails through the mouldings to knock out the 'break through' that would inevitably prevent the moulding from sitting flat" mean?

And then you say "knock the points flush with the glue face again." What is the glue face? I'd think that's the back of the molding, which sits on the glue line; but that doesn't make any sense to me.

And how does a "couple of taps with a hammer will secure them without disturbing the glue's bond" happen? Are you tapping on the molding with a hammer?

Thanks,
Pam

 

[Jack Plane]

If you drive a cut nail through a piece of wood, it breaks out a little bit of the wood at the exit point – the 'break-through'. If you place a moulding on a carcase and drive a cut nail through the moulding, the break-through will more than likely become lodged between the moulding and the carcase, preventing the moulding from sitting flat on the carcase.

If you pre-nail the moulding i.e. drive the nails into the moulding so their points dislodge the break-throughs (stubborn break-throughs can easily be picked off with a fingernail), then that eliminates that issue.

The points of the nails must then be tapped back into the moulding prior to applying glue to the moulding's glue face so the moulding can then be rubbed onto the carcase. The points of the nails are right at the glue face, so a couple of taps with a hammer drives them sufficiently into the carcase to hold the moulding with minimal disturbance of the rapidly setting glue. Final setting of the nails can be done after the glue has dried.

 

[pampine]

Oh, that break through. Thanks. I understand the rubbed joinery, do it a lot myself; but is there some reason you don't set the nails immediately after? Is it because the nailing might separate the glued pieces?

Pam

 

[Jack Plane]

If the glue is still 'wet' and the mouldings are perfectly straight and flat, then I will drive the nails in at the time of gluing. If, on the other hand, the glue has begun to gel and/or the moulding has a slight twist or bow, I won't set the nails until the glue is dry... just in case.

If unsure, I would urge to adopt the latter approach.