|
Posted by Greg on February 4, 2007, 9:11 pm
>
>
>
>
>
> > Hi,
>
> > I am helping my boss apply molded concrete textured stone on his
> > family room wall. We have spread the base mortar and it is dry.
> > Today we started applying the stone. We are using a portand cemet mix
> > with clean fine sand.
>
> > I don't know, but I believe that mortar is like creme brule (i.e.,
> > very sensitive). It demands crystal clean water and just the right
> > amount of mixing. It should be used fresh and spillage shoud never be
> > thrown back on the butter board for reuse. The boss (perhaps he would
> > skin a flea for its hide and tallow) is like a busy bee scoping up
> > spillage and mixing it back in our fresh mortar.
>
> > I know it is his mortar and his wall, but I would apprecriate some
> > corraboration that his miserly habits may result in unstuck stone
> > falling on his beautiful Italian tile floors. Thank you.
>
> Adding old to new mortar changes the setting time, adhesion, and
> working characteristics. This may not matter on many jobs, but on
> critical interior work it can make a significant difference. A skilled
> mason will reuse a certain amount of sluff, but if you watch
> carefully, sometmes he will discard a bunch and yell at his hod
> carrier for 'more mud'. He knows from experience that it is no longer
> 'workable'.
> A similar situation occurs with plaster of paris for well known
> reasons. The initially formed hydrated crystals catalyze the formation
> of more to complete setting reaction.. Setting type drywall compounds
> take advantage of this to tailor the setting times by varying the
> amount of initial crystal content.
> Good advice for your boss: You fight chemistry, you lose. HTH
>
> Joe- Hide quoted text -
>
> - Show quoted text -
Thanks all for your replies.
| 
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap