Hoffman Router

[Framernathan]

I am interested investing in a Hoffman router but I have a few questions. I was hoping some Hoffman users could give me some advice.

I understand the Hoffman is good for joining harder woods but on softer woods does the Hoffman give a superior join to an underpinner? I'm interested in spray painted finishes. Does the Hoffman give a tighter join?

I'm trying to decide if the Hoffman is essential equipment or whether its main benefits will be convenience and time saving.

Also are they particularly noisy? Out of interest.

[prospero]

Firstly, I've not got one or ever used one.

But the advantage as far as I can see is on deep, narrow moulding such as use on box frames. These mouldings are
hard to stack v-nails into. Particularly oak/ash. They frequently require cross-nailing near the top, with a single v-nail
in the bottom. A Hoffman key provides support along the whole depth.

One snag as fer as I can see. The keys are plastic, which means they only provide mechanical support and reduce the glued
surface quite a lot on thin mouldings. Just a thought.....

[Justintime]

Hi Nathan,
I've been using a manual MU2 for about a year, having started out with a Casesse foot operated Uni cart.
I bought it primarily because I was not getting satisfactory joins on Ash and Oak with the underpinner.
Hoffmann say that the keys are designed to hold the join together while the glue dries. This allows you to adjust the join after having tapped in the key, which I find really useful.
I have used my underpinner 2 or 3 times since buying the Hoffmann.
I don't find it quicker than an Underpinner, its probably a bit slower, but I never have to cross my fingers like I used to.
As prospero rightly says, it is also incredibly easy, once the router is set up correctly, to join tall and skinny mouldings.
The W1 router bit comes in standard and slightly larger(which I use) and now the W0 which is a tiny key. I've used the W0 on Rose and Hollis SW3850 and am told it can be used for A140 as well.
If the key is too tight in the routed hole, it can split tulip wood. That's all down to setting up the router bit right.
For me it's now essential and only time saving in that I don't ever have to clamp frames overnight anymore. The manual process of glueing both sides , hammering in 4 keys and adjusting the join fractionally if required, that's slower.
The only sound is from the 1000 watt router motor, which is designed to run only when actually routing out, so in short bursts.
If you're joining 35mm deep or larger I recommend getting the tall support fence for it.
Hoffmann have a number of good videos online, showing the steps. It really is as easy as it looks.
Hope that helps!
Justin

[Tudor Rose]

We have the MU2P. It hasn't stopped us using our pneumatic underpinner which we still use a lot, but we do use it on certain mouldings - anything at all in oak or ash for example. Justin has given you a pretty good run down of the benefits. There is a bit of noise and a bit of dust, but all that is manageable.

Not only is it good on tall thin mouldings and hard woods, it is also really useful on very wide mouldings. To try to answer your original question, there are plenty of mouldings where an underpinner will perform just as well as a Hoffman. It is one of those bits of kit where you can get away without having one, but once you have it you find it really useful.

[Framernathan]

Thank you for the information. I have to say I'm torn. I'm sure I'd use it and get good use out of it, but is it worth forking out the money for?

Underpinners are great for most joining and I've never had a problem joining the harder woods as drilling and knocking in a nail usually gives a solid join. One benefit I can see with the Hoffman on flat mouldings would be that the two pieces should join with the surface side level, so slight variations in height won't be too much of an issue. It that correct?

I like the sound of joining A140 on it which is a bit of a pain to join. I love that profile for it's narrowness but the corners are always tend to open using nails.

[Justintime]

One benefit I can see with the Hoffman on flat mouldings would be that the two pieces should join with the surface side level, so slight variations in height won't be too much of an issue. It that correct?

Yes!
I have to say that a friend who gessos his frames is having issues with the gesso cracking on the corners sometime after. I think his joins may be too tight to begin with which may be causing the problem..
Maybe if I had bought a pneumatic underpinner to begin with, I wouldn't be such a convert?

[Framernathan]

Justintime - Are you saying the Hoffman makes the corners more likely to crack? Eeeeeeeek! So he had less of a problem when he used an underpinner? If that is the case, I think I'll save my money.

I think gesso will always crack in the end. Has your friend tried gluing silk over the join? It helps a little. Just use very fine close-weave silk, the thinnest you can find.

[prospero]

The cracking on wide mouldings is due to shrinkage. If you store your moulding in an unheated area and bring it into
a warmer workshop to cut/join, then you run the risk of corner cracks. Wood shrinks across the grain as the moisture
content reduces. Pine and related Softwoods tend to be the worst and the wider it is the more it will move.
I tend to leave the cut rails for a day or two, particularly in the winter to 'normalise' before joining.
Funny stuff wood.

[Justintime]

Are you saying the Hoffman makes the corners more likely to crack?

No, not unless the join is too tight.
I'll pass on the tip about the silk.
He thinks that underpinners are the work of the devil!! He was trained old school, hammer n nails.
He decided to use deep thin tulip moulding for his own very large photographic prints, with subframe etc, he does ask a lot of his frames!
I think prospero has hit the nail on the head, his unheated workshop...

[Framernathan]

Justintime - I find underpinning joins very well on tulip and obeche, although I can't stack v-nails as high the Hoffman can route.

Prospero - I store my timber in the place I cut. I might try leaving the cut pieces for a day or two though. I do notice corners moving overnight when the temperature has dropped.

[poliopete]

In addition to the good advice by prospero regarding acclimatizing moulding/timber, I find glass cuts easier in this cold weather, if you cut it later in the day when your workshop has warmed a little. Keeping your glue warm as advised by Lion is also good practice.

[Framernathan]

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