How to Harden Sticky Resin (Other Similar Issues)
It's understandable that you'd easily get discouraged when your resin projects turn out to be sticky. What measures would you take when your resin didn't cure properly? IntoResin prepared a few methods for you to harden your sticky resin.
Conditions of Uncured Resin
Condition 1: Sticky Resin
You should know the epoxy passes from the liquid state, through a gel state, before it reaches a solid state. Sticky resin is the condition that your resin didn't cure completely (gel state) and the surface is still tacky. Chances are you didn't measure your portions correctly, mix them thoroughly to create the necessary chemical reaction, or leave them in warm temperature.
Condition 2: Runny Resin
Runny resin is the condition that your resin just cured slightly and the rest of it is still in liquid state (looks like fresh mixed resin). It's not that sticky but wet.
Condition 3: Soft Spots
Soft or sticky spots look like uneven spots on the cured resin surface.
Why it happens
Incorrect Measurement: Follow the resin ratio instructions from the manufactuers. Always measure IntoResin in precisely equal amounts, by volume.
Incomplete Mixing: At least take 3~5 minutes to mix the resin thoroughly so chemical reaction between the resin and hardener was able to take place. Keep in mind that scraping the sides and bottom of the mixing container.
Low Temperature: You should know the appropriate temperature of resin curing is 75-85℉(24-30℃) for the first 24 hours. Especially in cold weather, the room temperature gets way lower than usual.
How to harden
Sticky resin is much easier to be fixed than other conditions. If you make sure that you measure and mix perfectly, then in all likelihood, the temperature is the reason. It is not warm enough so the resin can't cure properly. Simply move the resin to a warmer spot and leave it another 24 hours to see if it cures.
If the resin is still sticky(no runny resin or soft spots), here's another trick: Pour a fresh coat(measured and mixed well) over the sticky surface and let it cure. Problem solved. Super easy!! ✌️
Why it happens
Not follow the ratio of resin to hardener: IntoResin provides best results if you ensure a 1:1 ratio by volume (equal parts). Adding too much of either resin or hardener will make your resin not cure properly.
Not measure by volume: IntoResin was formulated to be measured in equal amounts by volume (most epoxy resin is measured by volume).
Mix 2 part epoxy or 2 part hardener: The chemical reaction will not be produced if you pour 2 part of either epoxy or hardener by mistake. You can fix it by adding another equal amounts epoxy or hardener so as to create so much waste.
Too much resin colorant: It is recommended to add no more than 6% of color from the total volume of hardener and resin together. If your projects needs 100ml compound, you can't add the colorant more than 6ml.
How to fix
Unfortunately, it's more complicated to fix than the state of sticky resin. Here are a few steps that you should follow:
Try to scrape off as much wet compound as you can, or it will leak out from the fresh mixed resin.
After scraping them off, figure out why it didn't cure and make sure you can exclude the above reasons.
Add a new coat of resin.
Why it happens
When you're pouring the resin into the molds, you possibly scrape the sides of the mixing cup where the resin is not thoroughly mixed. We did recommend that you need to scrape the sides and bottom when you're mixing the resin, but we don't recommend that you should do the same thing when you pour the resin. If any unmixed resin or hardener gets scraped onto your molds, then it will turn out to be the cured resin with some soft or wet spots.
How to fix
Remove as many wet or soft spots as you can. (you know the reason)
After scraping them off, prepare coarse sandpaper (80 grit would be better) and sand down the cured resin.
No worries about producing the dust on the resin surface. Just take a wet paper towel and wipe them up. When you've done this, just go to mix another new resin (make sure you measured accurately) and pour them over the surface.