Front Rail Bushings

[David Skolnik]

I'm confused or curious about a few of the responses to this question.
 From John Delacour come the information about the greater efficacy 
of cold water in softening hide glue.  Can John explain why this 
would be so?  If we are already using Dif and or alcohol as wetting 
agents, there should be no reason to use hot water, if its only 
purpose is to overcome surface tension.  Also, regarding Bill 
Spurlock's sizing cauls, which I use, I wonder...I can see how they 
would work if you want to reduce the mortise size to a uniform width 
by wetting and glue sizing.  The fibres are expanded and then fixed 
in their new dimension by the glue sizing.  However, if the minimum 
amount of water is applied to wet the cloth and glue, without 
over-saturating the wood, there would be minimal dimensional change 
in the wood to begin with, thus making the cauls superfluous?  If the 
wood IS saturated, the expansion would seem to have already taken 
place by the time the bushings are removed, especially if they are 
left for a number of hours, as some of the posts suggest.  In that 
case, what is happening to the fibers as the key drys?  Do they 
return to their original dimension or do they remain expanded?  If 
you insert the sizing caul into the wetted mortise after removing the 
bushing, what happens? Fibre crushing?  If the caul is tight when 
wood is wet, and loose when dry, how much control is there over the 
amount of shrinkage?  Is there a glue sizing effect from residual 
glue?   Wouldn't it be more consistent to allow the wood to expand 
(stabilize) and then go through with a sized file when dry?

If I dug up Spurlock's instructions, I'd probably want to unsend the 
above.  Oh well.

David Skolnik
Hastings on Hudson, NY



At 06:27 PM 4/14/2007, you wrote:
>At 3:04 pm -0700 14/4/07, Matthew Todd wrote:
>
>>What is the best way to remove front rail bushings if I'm not 
>>replacing keytops.  The reason I ask this is because the way I was 
>>taught to remove the bushings was with a hot iron and damp rag. 
>>Well, that'll work fine if I'm replacing keytops at the same time 
>>since the steam will work the tops loose.  But I want to remove 
>>front rail bushings only, and I want to find out something that 
>>will work better.
>
>I have never used steam to remove anything in 35 years.  Use hot 
>water with a few drops of detergent to soak the bushings, leave them 
>for a an hour or two or for as long as it takes and then lift out 
>the bushings with flat nosed pliers.  The whole job will take less 
>than half an hour.  Needless to say, the water that actually does 
>the work is by then cold, and anyone who works with animal glue 
>knows that glue is softened more quickly with cold water than with 
>hot.  The purpose of using hot water is simply to overcome surface 
>tension so that the water soaks immediately through the cloth.
>
>I used to use an eye-dropper or pen-filler to apply the water but 
>quite recently invented a new tool and made one also for a colleague 
>of mine, who has now told me three times how pleased he is with the 
>method.  I'll take a picture when I can find it, but the principle 
>is that of an old dip-pen.  The tool is made from a bamboo chopstick 
>(a hammer-shank will also do) with a slit that will hold just enough 
>water to soak one bushing.  When you dip it in the water it picks up 
>just the right amount and when you touch it on the cloth, that water 
>is drawn into the bushing and there is no spillage.
>
>JD
>
>
>