The Framers Forum

A few questions for the wise folk out there.

1. I have a minigraf 3 underpinner, fairly old, which I bought second hand not too long ago. It came with just a 10mm head, and I'm wanting to get some other sizes. On looking at the different heads it seems that I shouldn't mix black/bare metal heads. Just so's I'm clear, I'm talking about the metal thing that the wedge is fired through. Where my confusion lies is that the inner part is bare metal, but the outer part is black. Does this mean I that the parts have already been mixed? or do I just need to replace the black part with a black part again?

2. I'm after quite a deep moulding with a rebate of around 55mm and a width of around 20mm. It needs to be bare wood, either oak or ash, or a dark wood like wenge. Anyone know anything?

3. last thing, I need a fillet for whichever deep rebate moulding I end up using which needs to be white. This also needs to be fully archival quality. There's plenty of wood fillets which I can cover, perhaps with paper, but is this enough? Perhaps a coat of gesso might be a good enough barrier. Any thoughts?

Any help much appreciated.

1. I don't think it makes any difference at all.

2. Rose and Hollis do a 22mm wide box with 40mm deep rebate, ref A42 in ash, oak, beech, tulip, and others. Or they do a 22mm wide with a 62mm rebate, ref A45 in oak, obeche, or tulip. I would just use the A45 and cut the back down to the required rebate depth. Piaf 2 mouldings could make exact timber and size needed.

3. A number of easy options for the fillet, use some strips of suitable museum mountboard, 3mm faced with a standard thickness board is a method we often use. Or use a wooden fillet, cover with aluminium barrier tape and then face with mountboard. Gesso is perhaps the most absorbent material in the world, so not really suitable as a barrier.

I would avoid wenge, not that easy to work with, lots of splinters (did you know that wenge splinters will often turn sceptic are are considered a health hazzard!?), and the grain pattern can be distinct.

When joining a oak or ash box of this depth, I would not try and stack the wedges, just a 12 or 15 with lots of good glue and a strap clamp to hold the mitres tight (or improvise with masking tape))) It is even worth drilling and cross pinning the old fashioned way.

Brilliant stuff, Thanks Mr. Framemaker.
I (hopefully) have some solutions making their way to me as we speak. Or type, I should say.
I don't really want to work with wenge, no, but if the customer really wants it, he shall get it. The wenge, I mean. Nothing violent.
Splinters are bearable though, a little magnesium sulphate solves them. Our native blackthorn is similar in that if the thorns are left in they can cause blood poisoning. Nasty stuff.