Hi everyone

Good discussion, and I might say one that is important if you are working towards a nice tight framework.

Proceedure for prefitting each bent at UCV and preparing it for the eventual erection day, was to ensure that all the pin holes were predrilled properly, and that meant using the drawbore method. Without this method the joints would be sloppy and allow the frame to eventually develop movement due to wind forces.

We would predrill all the holes through the timbers at the exact location of each mortise, being careful to get them as straight through the timber as possible.

The next step would be to slide the tenon into the mortise until it bottoms out on the sizing lines.

Dropping a hand auger then into the predrilled holes would leave a tell tale marker point on the tenon, we then would slide the tenon out of the mortise, move over the bit approx 3\16" towards the shoulder, and again carefully bore the hole through the tenon.

Too much draw could split the timber so one had to be careful as well.


One point that I would like to focus your attention on is during this fitting and boring process it was very important that the whole framework was as level as possible, so that the timbers as you slid them together for the fitting, would be tight across the whole face of the seating (where they meet), especially on the down side that was not observable from the upper working face



NH

tim,

good point about offsetting the tenon to keep the holes accurate if you are drawboring by the numbers.

we've been scribing mostly for a while so our tenons are pricked when the bent/wall/truss is assembled and then pulled apart and the tenons drilled.

if we're square ruling, if the surface is pretty good, we use either a drill guide or on irregular stuff, we level the stick use a level to guide the bit.

Hi Gabel,

I might just owe you an apology !

I was inside "The Mount" Silchester today in Northern Hampshire. This is a 3 bay cruck house dating from circa 1405 i.e. 600 years plus old and I paid particular attention to the arch braces fitted on the central open hall truss and noted that tapered pegs had been used which of course implies draw boring. Where draw boring is employed then the peg holes are full on the driving side and only partially full on the exit side. That was the case at The Mount. With parallel pegs the holes would be full on both the upper and underside faces. The cruck blades are "see sawn" halved from one tree to make a book matched pair and are only about 7 - 8" thick with wane on the back face so these blades are a bit short of 12" posts that I was previously thinking about.

This finding should not be taken as substantiation of a general rule but I will now fastideously check each centre line mounted arch brace that I encounter and especially those fitted to wide posts and report back on outcomes found.

I can send pictures to anyone who has a particular interest in this kind of feature.

Regards

Ken Hume

Hi Ken,
I would like to see some pictures if its not to much trouble.
karl.hines@glv.com

Thanks.
Karl

Same here Ken, I believe you have my email info. Thanks, Tim

Thanks, Ken. Your web site is an inspiration.

As an way off topic side note, were the bricks in the photos white washed with a lime wash? Tim

Hi Tim,

Limewash has been applied to both the wattle & daub and brick noggin infil on the Queens cruck timber frame shown on our website and we noted that the frame had been painted red at some time in its long history.

Regards

Ken Hume
http://www.kfhume.freeserve.co.uk

hey everyone, as far as the drawboring, I have always prefit, mark the tenon and drawbore, assemble. I have seen the tilt method that derek speaks of but i personally like offsetting and then drilling perpendicular to tenon. If you want to make an accurate mark. Take a peg the same diameter as peg hole find the center of the cylinder on the endgrain then offset a driven nail. Grind the nail head off and make the shank a sharp point. To the point on the circumference where the nail is offset draw a line along the length of the peg. When you put the peg in you can use your line to direct precisely. Tap lightly and you have a good mark. I like watching the 1/16 draw tight.

If you have intersecting timbers that are not perpendicular do you all drawbore towards the nose or square to the shoulder?

In this case, you draw bore in two directions, such as with a brace.....

mo, nice description of the tool to lay out your drawbores..
and I agree with Jim, angled connections are double draws, generally the drawbore follows the grain of the tenon.