We have laid a penny floor and 42 hours ago we sealed it with the glasscast 3 resin. However we are  little bit concerned that 42 hours later, although most of it is rock solid there are still a number of sticky patches remaining is this normal??

Hi Dawn

Thanks for getting back to me.  Its a real shame you can't get enough of the mess up to be able to leave the pennies in place..  That is a lot of extra work and I can completely understand how soul destroying that must be.  I would seriously consider another attempt at cleaning the  resin off, even scraping it off as a gloop then using acetone to soften anything that's too hard to easily scrape off. Unless the resin has fully hardened, I would expect it is easier to get the resin off the floor than the bonded down pennies off the floor.    If you have to remove the pennies, you can use acetone to wipe down the coins, although only  use what you need rather than soaking the coins for a period of time.  Most solvents or acidic/caustic cleaning agents will strip off the  oxidization off the coins leaving them as new. - coke is a classic  example of this - a few pennies left in a glass of coke overnight will  be shiny and clean by the morning in most cases. 

Doing a bit more investigation, I have checked the batch of resin and hardener you were supplied and we have sold over 1 metric ton since receiving that batch with no reported issues so far (it is our most popular product so we literally sell many tons per year). We have even used the same batch in some pigment experiments with no issues so I can be as confident as possible that the resin itself is unlikely to be a defective batch.  The way we decant and bottle the resins is such that it would be again extremely unlikely that some additional contaminant could get into it causing issues with just your specific bottles (or a small quantity).  That leads me to believe that the only reasonable explanation is a problem with the process or a simple error at some stage which has caused the issue.

From reading the description,  did you measure out each part by weight on scales or pour it directly into the bucket?  If the later, depending how much of the dregs you got out the bottle, you might have a slight error in mixing ratio, although  in this case I suspect that alone would not cause the extent of your issues. 5kg is a bit big to mix in one go in our opinion.  We tend to recommend mixing in batches of 3kg or smaller due to practicality issues.  It is physically quite hard to mix a 5kg batch.  Also simple things like using a relatively small mixing stick, round stick or something with a small surface area can all lead to making the mixing less accurate, even if you did mechanically stir it for the recommended time. For example our resin mixing stick we recommend has a large flat surface which is sized perfectly for ensuring the resin is suitably mixed at the recommended batch size.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant