I used a pump for my project.  I checked it's accuracy (by volume) monthly for six years.  It remained accurate the entire time.  It is much easier to pump out a certain number of pumps for a given layup than it is to measure with a scale.  If you keep track you will soon be able to accurately estimate the number of pumps for a given area of fabric.  If your pump is sticking it may not deliver accurately and you should spend the money for a new one.  I believe they sold replacement pistons for less than the entire pump.  You should keep the pump at a constant controlled temperature.

David







Scale hands down.

Jim



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*From:* Lancair Mailing List [mailto:lml@lancaironline.net] *On Behalf Of *WILLIAM HOLDEN
*Sent:* Thursday, September 24, 2009 9:07 PM
*To:* lml@lancaironline.net
*Subject:* [LML] Pump vs. Scale for Epoxy mixing



What are everyone's thoughts on using a pump versus a scale for epoxy mixing?  I have a pump that I bought used and can't seem to get it working smoothly despite a lot of cleaning.  Seems to me a scale and cups are easier to keep clean and monitor rather than the pump?  Any thoughts?



Will