Is mixing resin by weight or volume really that important?
Resin is a two part component that is mixed with a part A, resin and part B, hardener (catalyst). The correct ratio is required to obtain a full cure. The ratio required is determined by the chemicals used in the resin and hardener. If the ratio mixed is incorrect it can lead to your resin not curing properly, soft curing or a chemical reaction that creates cracking and shrinkage.
Depending on the resin used it can be mixed by weight or volume but its important to note that these measurements are different. As the density between resin and hardener changes, the ratio by volume will be different to the ratio by weight.
As the resin world goes of with a boom we has such a wide variety available. Some are mixed by weight and others by volume, there is no one size fits all.
If we take a look at the resin we stock at Australian Beach Resin we have ensured a uniform pattern and all are measured by volume. When measuring by volume it is very simple, providing you have the have the right tools. Measuring cups are so important and you will go through a bunch so keep a small supply handy. Here are some examples
1:1 by Volume means equal parts by measurement. So say you need 200ml for your artwork you will mix 100mls part A and 100mls part B.
2:1 by volume means 2 parts A and 1 part B by measurement. If pouring a river table and you need 3lts you will mix 2lts part A and 1lt part B.
If you are measuring those same resins listed above by weight the correct ratio will be measured on a scale. Its important to note that the resin you use should clearly state on the label if it is to be measured by volume or weight. If you take a look at our Australian Beach Top Coat it is recommended that it be mixed by volume but it can however be mixed by weight with some small adjustments in ratio.
As it is a 2:1 by volume you would take 200mls part A and 100mls part B and mix in a measuring cup by volume.
If you were to measure this same resin by weight you would need to take 100mls of part A and 43mls of part B by weight, on a scale.
As you can see it is totally different figures on paper. Put it all in a cup and it will be the same but if you were to take Australian Beach Top Coat and weigh it on a scale at 200mls part A and q00mls part B, your ratio would be completely out of wack and you would have major issues when curing.
So at the end of the day...YES it does matter if you resin is mixed via weight or volume. Take note and follow the label instructions. If it is unclear contact your supplier and ask questions. Make sure you mix the correct amounts and scrape down the sides multiple times when stirring.
There are so many variables when it comes to resin, this is just one. Keep an eye out to see what's in our next article.