The Framers Forum

Hello,

I have recently started framing and I am having trouble pinning mouldings on my Kimberley underpinner.

Whilst the cut pieces go together nicely when placed on the work bench, they "gap" at the edges when pinned. The top/facing of the moulding is fine, but all 4 sides show this spacing.

I wondered whether anyone would have an opinion on what I might be doing wrong? I am using an ash moulding (I wonder whether this underpinner struggles with hardwood mouldings?).

Many thanks for any help!

is your underpinner a hand operated one?

Hi, yes, it is. The pieces are clamped in and pinned from underneath.

Sometimes having the wedges to close to the back of the moulding (outside edge) can cause a gap. Most gap issues when pinning are usually incorrect wedge type (you need hard wedges for Ash), wedge position or incorrect pressure. A lot of pneumatic underpinners can struggle with Ash, personally I can't really imagine trying it on a hand operated underpinner, I would have thought it would be difficult to get enough pressure.

I don't think that there's much chance of getting a worthwhile result trying to join ash, or oak on any hand operated underpinner, regardless which make you have bought, but don't be downhearted, most moulding suppliers have ash veneered mouldings with a softer variety of wood inside. Get yourself an ash veneered moulding instead and the job's a good one!

As I keep saying, check first that your mitre cuts are really accurate. A final very fine shaving cut is essential for those hard-woods.
After that, if the underpinner is pushing back on the mouldings, then it's glue, frame clamp and hammer and nails.

Thank you all for your responses; I will have another look tomorrow but suspect I have chosen an over-ambitious moulding for a beginner.

Although I have a pneumatic underpinner I much prefer to join solid Oak and Ash the way Vintage frames and others suggest

Your Kimberly underpinner is a superbly designed and well-calibrated piece of kit but it does have limitations. As you say," the cut pieces join nicely when laid on your workbench" if they are sill join nicely in the vice of your Kimberly then side pinning is the solution.

My method is to glue, drill a small pilot hole, pin with the appropriate size veneer pin, punch the pin home, fill with a mixture of glue and Oak/Ash sawdust and sand smooth. I like to join two lengths and leave the glue to cure. Then the other two lengths are joined.

This method is a little time consuming but worthwhile as mounts, backs, and glass can be cut in the meantime.

Peter.

Sorry, I should have added, "welcome to the FF "

Peter.

This sounds like a classic symptom when pinning hard woods. They need a lot of pressure on top.
What happens is, the hammer drives the v-nail up and when it contacts the wood it meets resistance. If the top
pressure is insufficient the the two halves of the joint lift and separate at the back before the nail bites. It then
continues into the wood and pulls the join together - so the front looks OK, Exactly as you describe.
(Your machine works differently I know, but the principle holds true.)
Underpinning Oak or Ash is always going to be problematic. I'm tempted to say use a mitre vice and drill/nail it
in the 'old school' manner, You'll get a much better join - albeit with a few holes to fill. Lesser of two evils IMHO,
nail holes in bare Oak/Ash are very easily filled and can turn out almost invisible.
The strength of a joint is in the glue, NOT the mechanical fixings. Think of the nails as a clamp to hold the faces tight
while the glue sets. Once that happens they continue to work in concert with the glue form a very good joint and to
protect the glue bond from stress. If the joint only meets at the front it will be weakened considerably.

With the pinner you are using you are really asking too much of it.

If you don't want nail holes to fill the a machine like a Hoffman router is the solution, but they are a big outlay and you need
to do enough frames to get your monies worth.

I had some success with glueing and clamping with a steel band clamp, leave overnight and underpin in the morning with the clamp still on!

I've never owned a frame-vise but for my frames, here's what I do.
Glue the corners with Titebond 3 ( all educated framers use it ) and put it into a band clamp.
Tighten it up a bit then, with a good pair of reading glasses, wiggle and twist the mitres until I get a perfect flush corner; then tighten up to full strength.
Next day, pre-drill the corners with fine Challenge panel pins, and hammer home the same pins to finish.
Two part wood filler will cover up all the workings.

Yes to Titebond 3, you put me onto it Dermot.
The only thing I'd say is that it dries brown rather than clear, so be careful with Ash mouldings, not to over do the glue as it can be a PIA to remove/fill to cover the glue colour, newbie mistake maybe..

Thank you all so much for taking the time to reply; it's been really useful and thank you for the welcome!

I wondered whether anyone could recommend an alternative underpinner? I could probably look to spend up to £400. I spotted an ex-demo Inmes 3 on Lion's website and wondered whether that would be any good for hardwood such as ash. I will give them (Lion) a call but any words of wisdom gratefully received.

Thank you again.

Best thing for hardwoods is a Hoffmann dovetail router. I got in touch with Hoffmann and they found me a secondhand one that I could actually afford (around £600). Your underpinner is perfectly fine for softwoods and worth holding on to.
Before the Hoffmann, I steel band clamped hardwoods with glue and underpinned the next morning. Ronseal multipurpose wood filler, natural, I think, is a pretty good match for Ash.
https://www.google.com/url?sa=t&source= ... 4qNCvzLtxw
If you haven't got one already, they are worth it.

Wow I must be an uneducated framer as we do not use the tite bond product, our extensive testing must have been in error.

Well why don't you share the results of your extensive testing IFGL, if something is better I'll use it!

Hi Glosframer,

I use Titebond

If you contact my brother Peter at Framers Equipment, he has second hand machines capable of doing what you need.

http://www.framersequipment.co.uk/index.htm

You can always take some samples or and try the machines out with his guidance, or post him some bits to join and advise.

Kind regards

Mitreman

One piece of advice given to me by the tech support guy at A&T was, make sure to hold pressure downwards ọn the Morso, not back against the fences. If you put pressure downwards on the Morso then underpin it'll be right,as the pressure is from below. If I'm going to Hoffmann it, then best to hold against the fence on the Morso, as you'll then hold against the fence on the Hoff.

You won't go far wrong getting Jans brother Peter to sort out something second hand to do the underpinning with. Peter is a top guy and used to look after the machinery and the Triton gallery framing workshop, while I was there. He gave everything in the workshop an overhaul, fixed all the little niggles and reorganised the whole workshop to increase the workshops overall efficiency and this included driving down in the morning and driving home all in one day. Seriously impressive!

Jan and Peter were pretty much born into this business. Their father and Pete Bingham ran the machinery division of Magnolia mouldings back in the 1960's or thereabouts and looked after everyone's machinery issues as far back as that. Triton had an old and seriously worn out Keeton mount cutter, which had not been produced for decades, but somehow Peter kept tracking down spare parts to keep it going. Eventually the boss agreed to buy a modern mount cutter when the gallery started using mount boards that were to dense to cut properly on the Keeton.

I don't suppose Peter is aware of this, but I learn a tremendous amount from him while he was at Triton during that day. Good on you Peter!