Maybe it was just the way I used the pumps but I found them very inaccurate and also rather messy. I guess that working in low temperatures may be one of the reasons for this - the viscosity increase at lower temperatures. From a chemical point of view, epoxy requires rather accurate proportion; i.e. the number of molecules in the A-component should match the number of molecules in the B-component. Now, imagine an 10 % error in the matching of pump A and pump B. This 10 % error will be constant regardless if you mix a small or a large batch of epoxy. The error will also affect the properties of the cured epoxy. When using a scale, the it's no problem to hit the right proportions with an 1-2 gram accuracy. If we mix a 20 gram batch we have an error of 5-10 % (the same as when using the pumps) - but if we mix a 100 gram batch the error will be around 1 %. That's a rather significant difference!
Anyway, which kind of boat do you plan to build??
Ahh, Greay Seal is a very nice boat - the final match was actually between #106 and the Seal - please start a thread! The shop is heated in many different way. I use a basal electric heat to keep the temp above freezing. When doing epoxy work, I use a diesel heater to keep a suitable temperature. It's no problem once you get used to working in a cold shop. When it comes to epoxy-work the cold Swedish temperature makes the air and wood very dry...
pros and cons!
/Fredrik


Reply With Quote
























































