Slot Mortiser--Can it do it?

[Peter Quinn]

Can a horizontal slot mortiser handle slots for interior/exterior doors? Considering purchasing a Laguna, wondering if it can do 1/2" and 5/8" slots 3 1/2" deep. Any thoughts?

[Charlie Plesums]

Talk to your vendor. I have birds mouth bits for my slot mortiser that are larger than that, but I don't believe they are that long. That seems pretty deep for any type of mortise and tenon... a deeper tenon than you could cut with most table saws (using a tenon jig), most routers, most shapers, etc.

[Scott Rollins]

I looked at this model as well. I emailed Laguna at least 4 times over 3 weeks to get some info on the unit. I never heard from them. I think their customer servise needs work. I ended up buying a Steel City Mortiser holow chisel mortiser. It works great.

[Peter Quinn]

When I emailed Laguna they sent me a highly informative but extremely boring video about their bandsaws, which I happen to adore and envy. No info about any horizontal mortisers (Laguna, Platinum, Knapp). They also sent me unrequested literature about a Griggio panel saw...strange?

I have made M&T interior/exterior hardwood doors at my last job using a bridgeport and I believe long 4 flute end mills. No power issue there. I am developing my own small business now and want to offer doors using loose tennons, I'm thinking 3 1/2" depth gives you 3" into the style after the mold cuts are made . Also interested in adding quicker doweling capacity.

I don't have a big enough shaper to spin shaper cutters for intregal tennons with cope cuts but would like to offer loose tennon construction as a quality upgrade over dowels. Has anyone had experience punching mortises this deep with one of these machines?

[Mike Spanbauer]

The only method I could see being able to do that deep (short of your end mill / milling machine solution @your last place) would be to use a heavy duty mortiser (such as the Powermatic 719 or the General... 050? can't remember the number.)

These units would be limited by the depth of the bit, but they have the power to handle those really, really deep holes.

That's a LOT of material and a LOT of stress on the bit at the length even with the power to spin it. I'd look for an alternate way myself as I suspect you're looking for production volume capabilities?

michael

[Peter Quinn]

I have used both of those machines, actually prefer the hold downs on the general. I have considered using a chisel mortise/stub spindle/intregal tennon set up but full size doors are only part of what I hope to offer. I am presently a full time stay at home Dad and am trying to develope my part time home based woodworking business. My own shop is 750sf with 250sf being added this spring, so a horizontal mortiser with dowel capacity is very attractive as a compact multitasking work station. 10-20 doors per year among other projects would be a good year!

At my last job production runs were typically 10-50 doors (1 3/4") cope/stick/dowel and smaller runs of 2-3" thick M&T custom doors. I think the shop was near 15,000sf. Lots of dedicated machines for each setup.

At home I have been using a dowel jig/pnuematic drill for cope and stick doors and loose tennons/plunge router for wooden storm windows. I have a drill press chisel mortise attachment for occasional light mortises. I have found ways to get most things done but would like to speed it up a bit. Even with a bridgeport and power fed table deflection in the bit was the limitation, so feed rates were slow and plunge depths stepped at 3/16"/pass.

I am wondering if any horizontal mortisers can handle slots deep enough for large doors. Am curious if the less industrial machines (hammer, rojek, Laguna platinum) are up to the task of light commercial production or if I should keep saving for a bigger machine.

[Ted Pritchard]

Peter
For a slot that deep and narrow, the only tool I've seen that could do it on a commercial basis, is a chain morticer (it uses a chain and bar like a chain saw).
Ted

[Peter Quinn]

Thats my fear Ted. I have a big industrial dewalt 1951 GR-14" RAS, and I'm told they made chain morticers for them that were quite effective but have never seen one for sale. Don't have space in my shop for a dedicated chain morticer, though maybe in the living room?

[Alan Turner]

Peter,
We did a commission which included 8 large, thick doors. We have an older Griggio slot mortiser, and had 3/4" x 5-1/2" 2-flute, spiral bits made for the task. We went slowly with the mortises, and they were fine. I think we went to about 3" depth, and used loose tenons. Our collet limit is 15mm. These were doors that were just under 10' tall by just over 3' wide. We used door core, and shop cut 1/8" veneer in sapele and walnut. Turned out to be a lot of work, but the doors turned out well.

Note that on some mortisers, there is an x-y-z- table, and on some an x-y-z- head. The latter is a distinct advantage. With a 10' stile, cutting the top and bottom rail mortises exerts a ton of force, trying to tip the machine over and cant the table. We built an adjustable height stand, and inset a strip of UHMW along the top edge, but it still took two guys for these mortises. I think Felder sells a HSM with the movable head, but am not sure. The newer Griggio's have this feature, but ours is the older model.

[Peter Quinn]

Thanks for the post Alan...the kick rail and top rail mortise issue is definitely on my mind now. I made a few long white oak stands with roller bearings on a top that can be leveled and plumbed to match an outfeed/infeed table and provide support. I work alone mostly, so my two helpers, "Bob and Dan I call them" often come in handy for supporting long work pieces on setups in motion. Not sure they'll give me the accuracy I need for mortises though.

I'm wondering even if work support issues can be overcome and tooling aquired if the motor on an entry level HSM is up to the task of punching 20-30 slots per door even on an occasional basis.

Question? When you refer to door core, is that a Timberstrand/LVL product? If so then carbide tooling is neccessary? Are your loose tennons hardwood, and what type of adhesive are you using when working with door core?

[Alan Turner]

Peter,
Door core, or stave core, is not LVL. It is basically a pine butcher block, and comes in "sheets" which are either 1.5" or 2" thick, 24" wide, and either 88", 106", or 124" long. Different sizes for different doors. It is quite flat and stable. We needed that for these doors as we were concerned that on stiles this long, there could be some twisting or bowing over time. And, 10/4 or 12/4 walnut is of quite poor quality right now, at least in our area for door stock, which needs to be quite straight grained. I believe that this product is made in Oregon, but the company I spoke with said they would not ship less than a truck load, and referred us to a firm in the NYC metro area which builds doors, and sells both the door core, and veneer for it. I think the order for 8 sheets of 2" stock was about $1200, delivered. We cut all of our own veneer, however. The stability of the stock we used was quite good. On a 10' stile, the runout was less than 1/16" over the full length. It took a lot of vacuum bag time for this job to apply the veneers. And, of course, you need to do your solid wood edging first. We used 1/2" edging for the outsides of the stiles, and 1/4" for the balance. We ganged these up for gluing, doing many at once with 24" clamps, letting the stock act as cauls to distribute clamp pressure. This went pretty quickly.

We did use hardwood tenons. We just beveled the corners on the tablesaw. There were about a million loose tenons as there were as many as 7 rails and 5 middle, short stiles on one pair of pocket doors. The glue ups were a three guy job! We used titebond original.

The cutters we had made were solid carbide, but HSS would have worked also, and perhpas have been stronger, but we went slowly on the mortising and had no breakage. I think these special made cutters were $200 each, and we felt we needed a back-up if we broke one so we could keep going. The job justified the cost of the tooling. One is unused.

Our Griggio has a 2 hp, single phase motor, belt drive, and it was not taxed. A HSM is thing of beauty for many jobs. It is easier to jig up than other methods of mortising, at least for us. On our table, which is cast iron, I installed a piece of 18mm BB ply, and drilled and tapped the table to hold it so there is no movement of the ply at all. I set it so that there is a 1.5" overhang on the sides, for clamping. This removable table lets you put a front edge of wood on it, and replace it as needed. Also, you can drill and tap the BB ply to hold things such as a 90 degree block, for cutting the mortises in the end grain. We keep a selection of 1/4 x 20 flat head socket drive grade 8 screws in stock for this kind of jig work. You can cut off a 5/32 allen wrench and chuck up your driver in a cordless drill so installation and removal is quick.

Hope this helps.

[Peter Quinn]

Thanks very much Alan...very helpful.