How to Mix Polyester Resin

Mixing polyester resin with its catalyst hardener must be done in a well ventilated, preferably outdoor, dry area on a day when there’s no chance of rain or snow. Also ensure the surface or product (matting and boards) that you may be putting the resin on is dry aswell. Ideally a cool dry day is best. This process should also be carried out away from any heat source or naked flames.

Firstly read all the manufacturers instructions, and health and safety information so you fully understand what equipment, and tools you need, and safety clothing to wear aswell as what to do in the event of getting any chemicals on your skin, or eyes, and even what fire extinguisher to use if a fire starts. Once your ready to start the mixing process select a suitable size mixing bucket e.g. a 10 litre bucket and pour the resin into bucket, then preferably using a measuring syringe, measure out 2% of catalyst, though depending on the temperature you can go as high as 4% if its cold and down to 1% if its particularly warm (anymore than 4% though and the resin can fail to harden. If its extremely cold then you could use an accelerator first such as D.M.A which is added at a ratio of 1% per kilo of resin, depending on conditions, but you must still use the catalyst straight afterwards, or the hardening won’t occur (though you must keep the two chemicals apart outside the resin as they are both highly volatile). Then pour the catalyst into the resin whilst stirring with a wooden spoon/batten, and continue stirring firmly until the resin becomes similar in consistency as you’d imagine stirring toothpaste! Curing time can vary from batch to batch so experimenting with a small amount first is a good tip, so you don’t get a large waste by making an error with a 20 litre bucket going off too quick!

Next your ready to apply the resin, depending on what its going onto, will determine what tools you use, however generally you’d use a lambs wool roller to firstly apply the resin to the job, and if it was going onto fiberglass matting then you would use a metal roller later, to disperse any air from within the matting to help create a flat even finish. Once your resin is dry, mix and apply your topcoat in the same way using a lamb’s wool roller. For an amateur this whole process does seem daunting with lots of possible hazards, but if you follow the manufacturers instructions and use safe working practises doing a small practice run first if you feel you need it, then there should be no reason why you can’t use these products time, and again, safely with great results.

Here at Speedy Plastics and Resins we pride ourselves on our great customer service, so whether you’re an amateur, or an experienced builder, I’m sure we could be of great service so please give our help desk a call on local number (0844) 8586670, and we will be delighted to help.