Hoffman Dovetail Router vs Cassese Underpinner

[Justintime]

Hi All,
Just looking for some advice.
I've been framing for about 9 months now, working a lot with hand finished frames, Tulip, Ash and Oak.
I am wondering whether I would be better off swapping my Cassese CS1 for a Hoffman dovetail router. As I was warned, the Ash and Oak are tricky to underpin, stacking wedges is not a reliable method. Although the steel clamp I recently bought from Mike Royall has saved me on a number of occasions, its not ideal...
Is there anyone who has replaced one with the other? Got rid of the underpinner altogether??
The only downside I can see, is that my relatively dust free framing studio will now have a source of wood dust...
Justin

[prospero]

The dovetail router is nice piece of kit. It really comes into its own when joining deep, narrow mouldings.

For joining profiles that need a stack of v-nails I tend to just use a single shallow one and then cross-nail near to
the top. A mitre vice is handy in these situations. OK, you have some nail holes to fill, but I don't find this a problem
and the filled holes are not obvious in most cases. If you are finishing the frame after joining, even better.
The big advantage is that all you need is a hammer, drill and centre punch.

[Framemaker Richard]

I've got a Hoffman router and is a great piece of kit, but I definitely still use the underpinner much more, and there are many barewood oak/ash mouldings that I still prefer to join on the underpinner, about 95% of my works is with barewood/unfinished mouldings. If I was just making box frames and flat profiles then yes, I would consider just the Hoffman, but I think it really depends what type of profiles you are joining.

[Not your average framer]

I saw a demonstration of the Hoffman router and was really impressed. I thought that it had quite considerable productivity advantages. If you are producing large enough quantities of hardwood frames, I think that it could save you a lot of time in the long run.

There are other similar machines on the market at different prices, if you want to check this out as well. I think that just about all of them produce their own dovetail wedges to their own designs, so the wedges are probably not interchangable between manufacturers.

[Justintime]

Thanks All,
Mark, what brands are you thinking of? Any spring to mind?

[Not your average framer]

There was a thread about this sometime ago. Here is the link:

viewtopic.php?f=6&t=9883&p=80491&hilit= ... ter#p80491

At the time, I found quite a lot about this online. Having just looked again, I have not found much at all. The other thought that I had was concerning the Fletcher Corner-Lock which is a similar idea. I did consider making my own machine, which I think is a practical thing to do and I might still do so at some time.

[Justintime]

Thanks Mark,
It doesn't look like the Genisis or Fletcher 4000 are readily available these days, so it's back to the Hoffman.
Having finished my day underpinning a 700x500 oak frame and have the wedges push the mitre open (again), the Hoffman is looking very attractive!

[Not your average framer]

How big are the mouldings that you are joining and what size are the actual frames?

[kuduframes]

The Hoffman is superb for many of the hard wood profiles but it will not replace the underpinner, you would need both.

[Justintime]

Mark,
Rose n hollis sw2724 Oak moulding, no more than 20mmx20mm, frame sizes 900mmx700mm/700mmx500mm(sorry, haven't mastered imperial yet).
I'm doing them one by one now, glue and clamp overnight, underpin next morning still with framers clamp on. Seems to be working, it's just that when there's loads to do...

[Not your average framer]

It's always a problem when there's loads to do. You can't glue them all overnight in band clamps, that would be crazy. I don't think that most framers have more than one band clamp, having large numbers of band clamps is just not a sensible proposition. On the other hand the Hoffman router and the dovetail keys completely solves that problem and makes good sense to me.

I too use the Rose & Hollis SW2724 moulding, so I know it well. The lengths of the sides on those frames can exert quite a bit of force on the corner joint, but customers seem to like picking mouldings for their looks rather than have adequate strength at the corners, so nothing new there. However, using the Hoffman router and dovetail keys reduces the available area for gluing wood to wood within the mitre joint.

Therefore is makes sense to use a really strong wood glue to compensate for the loss of gluing area. I think that you will notice a big improvement in productivity if you get the Hoffman. Probably not a difficult decision I think.

[prospero]

I've just done a couple of Ash frames - simple square profile about 22x22mm. I put one 7mm (soft wood) v-nail in
near the middle and cross-nailed near to the top. I did have my trusty mitre vice to help.

Without a vice it's still possible to nail but you have to be careful not to displace to joint. Drill pilot holes and put in both
nails and tap them alternately, making sure the far end of the rail is braced against something solid.
I filled the holes with Brummer stopping which made a good job of it. I stained the wood before joining but varnished it after. The
holes are visible but not obvious.

As for the Hoffman joiner I think I'm right in saying the keys are moulded plastic. I've sure I've seen some wood ones, which would be
far superior as far as the corner strength goes.

[Justintime]

Mark
Yes, more than one clamp would be extravagant.
Framer friend told me Titebond 3, superstrong n waterproof, so that's what in using.
I'm going to have a demo on an MU2 tomorrow although I'm aiming for an xline 20.
Prospero
I'm getting a demo on pinning the mitres tomorrow too. Don't have a vice or experience pinning yet..
Yes, I heard that wooden dovetails are better, but I don't know which brand uses them. Do you?

[kuduframes]

I suspect you might change your mind on the plastic dovetails when you see the Hoffmann demo.
The W2 size is the stronger key but on a 20 x 20 moulding you will need to be careful where to position the router slot, don't go too close to the outer edge or you may get the moulding breaking away.
I'm sure the demo will cover that. Are you doing the demo at Lion ?

[GeoSpectrum]

Hoffman supply wedges in hardwood and aluminium. The wooden ones are available in a a number of different types of hardwood. It's bought by the meter and you cut it down as required.

[Justintime]

No, demo is at a Framer friend's place he's had the MU2 for a couple of years.

[prospero]

I've done a bit of digging and it seems hardwood keys are available, but they are only intended as plugs to cover the plastic ones
when they would be visible. Quote: " They should not be relied upon as the only fastener in a given joint."
That seems a bit odd to me but what do i know?

Furthermore I can only find them on US sites where they are sold in lengths.

[Jamesnkr]

However, using the Hoffman router and dovetail keys reduces the available area for gluing wood to wood within the mitre joint. Therefore is makes sense to use a really strong wood glue to compensate for the loss of gluing area.

I was going to write: "a mitre joint is a pretty rubbish joint at the best of times, and surely the key will increase the available surface area for gluing - as well as providing an additional mechanical method of holding the joint together." And then I read the rest of the thread... and see that they don't work anything like a biscuit. I am quite surprised, seems like a missed opportunity to me.

[Framemaker Richard]

The plastic keys are much stronger than the wooden ones, these are intended for appearance only, and is recommenced that they are not relied on for corner strength or integrity.

[Justintime]

Wow, you've used them on the front of the moulding, that's a surprise, wasn't expecting that. Looks like it might be a bit distracting to the work?
Has anyone switched over solely to a Hoffmann for their joining?