Spurlock shimming method.

[Wilsons]

That's doin' it right!  :)

Wally

At 03:57 PM 5/1/01 -0400, you wrote:
>
>In a message dated 5/01/2001 10:58:09 AM, Larry T. wrote:
>
><<"I found that I could follow the crack with the angle aluminum even though
>the crack was not straight.">>
>
>This comment of Larry's leads me to make a few comments vis a vis Spurlock's 
>shim system and shimming in general.
>
>First..if there is a better shimming system/method on the market I am not 
>aware of it. However it does have its limitations .....though most of those 
>are limitations of 'operator' imagination rather than limitations of the 
>system. I know about this
>'operator limiting factor' from personal experience! :-)
>
> Can 'significant' crowning be acheived in the process of 
>"shimming"?..........probably not...but 'significant' tension can be added
to 
>the crown in the process of shimming. The wider, or more numerous, the 
>shim(s) installed the more prominent the added 'tension' will be. Consider 
>the 'shimming' of two boards.... one shimmed without the board being 
>wedged/propped/jacked up and one with said wedging/propping/jacking during 
>the shimming process.
>
> A board shimmed while 'flat' will have little or no added tension from the 
>shimming process and may have 'less' tension when the shimming is completed. 
>Think about it..if the crack is widened on an unsupported board is the crack 
>going to 'tend' to be moved down during the widening? If a shim is then
added 
>to the widened crack...... to what dimension is the shim fitted to? Will it 
>be the cracks size when the board is at rest or the cracks size when the 
>board is pressed down while pressure is applied to the shim to fit/glue it
in 
>the crack? Or will it be the size of the crack as widened with the board at 
>rest?
>
> Conversely on a supported board..... a crack widened and shimmed before the 
>support is removed will have more incidental tension in the boards 'at rest' 
>state. This because the crack will have been widened while the board was 
>under reverse, or crowning, tension from: wedging/propping/jacking. Does
this 
>count as much as "adding crown" to a board?.......no probably not...... but 
>it 'should' be better than having an essentially 'flat' shim 
>installed.......shouldn't it? ("flat" being defined as a shim installed 
>without board support)
>
>(I would think that these same general thoughts would apply to 
>polyester/epoxy methods as well when those are functional and not "cosmetic" 
>cracks, but I have no experience in that area.)
>
> Which is better a 'tensioned' shim or a 'flat' shim?
>
>As for following curves while shimming...........if it works for you go for 
>it but it might be better to install a straight shim instead. This applies 
>when using the Spurlock system, of course. I have used Bills' system to 
>install entire board sections/panels in S&S where the panel was infested
with 
>all those cute little curley-cue cracks/pressure ridges/separations, etc. 
>Using the Spurlock system it is as easy to install a 1, or more, inch 
>shim/insert as it is to install a 1/4 inch shim/insert.
>
>As a result of the above I try to never shim an unsupported board, even for 
>purely "cosmetic" cracks and I try to remove as much of the board as needful 

>when shimming a functional problem.
>But this is just my view.
>Jim Bryant (FL)
>