Creaturiste's Laboratory

Techniques, works in progress, and everything that doesn't fit in the portfolio. Comments and questions are encouraged, custom orders are welcome!

Thursday, July 1, 2010

Epoxy Putties

Hi there,
I've been using epoxy putty again tonight , because it was called for.
I thought the following input could help people have a better experience with this useful but "particular" category of materials. Things can go wrong real fast with epoxies.

I use it rarely, but it's great for some specific uses, such as:
•strengthening mechanics inside puppets
•gluing or merging parts of very different materials (even for glass to wood to metal!).
•Smoothing and patching an otherwise hard-to-repair material (only if paper mache is not suitable, such as for certain synthetic materials that are too slipery).
For most other things, such as a main modeling or casting material, I avoid it , because it is:
•Way too heavy
•Way Too brittle
•A nightmare to paint (scratches off too easily, no matter what primer I ever tried)
These problems have been consistent with the three different brands I tried:
•Apoxie Sculpt
•Mighty Putty

And one more epoxy-based casting product, of which I have not been told the name, seems to share these issues with the putties.

Three days ago, a heavy hollow puppet head from a colleague, cast in a supposedly flexible and lightweight epoxy material, got severely damaged when it was dropped from a table. The product had been highly recommended by another colleague of his, who got him the contract. BIG mistake. Caused a slew of technical problems for him and me, as well as puppeteering problems for the puppeteers (mostly weight and fragility, but also some air bubbles in the cast).

So tonight, to help out, I repaired the head with epoxy putty.
It's curing now.

The big problem I had with the only putty I had access to tonight, after hardware store hours was Mighty Putty, which I got at the drugstore. The price was right for a change, but that may have been because it was old stock. No mention of it anywhere, but I know from past experience that this is what happens to putty when it spends too long on the shelf: sets way too fast, gets brittle and loses adhesion properties in 5 minutes (or less).
A proerly fresh epoxy putty feels like warm bubble gum at first, is actually droopy for a minute or two. Tonight'"s stuff was already like firm modeling clay, and only sticky for two minutes or less. I wasted nearly half the package, because that's how much I mixed at once, and it set within 5 minutes, instead of the "minimum 20 minutes" advertised in the instructions. Next time, just because I obviously should not trust stores or suppliers, I shall mix a tiny amount at first, to test the batch.

I'd appreciate it if people with different experiences with epoxy puttie would come froward and share their tips, so that visitors here can benefit. Especially if you know of a good, not-too toxic primer to use on the stuff.



Ed said...

Hi Mathieu,
I use West System epoxy and the resin is like honey. It's useful for gluing and impregnating fabric.

When you need putty, you mix a thickening powder into the resin. You can make it the consistency of mayonnaise, peanut butter, etc.

Some of these fillers are like microscopic styro beads which are very light and easy to sand. Some are for bonding, quite strong.

And since it's West System, it all works marvelously.

Monica of the Masks said...

I have had fabulous results from Magic-Sculp two-part epoxy resin made by West Coast Taxidermy Suppy Co. Paint sticks great to it, both with or without primer, and it is strong and easy to sculpt with. Shelf life is great too, I have had a couple of containers on my shelf for over 5 years. When it gets stiff or chalky just stick the container in the microwave for a bit and it softens right up. Good luck!

Créaturiste said...

Thanks very much Ed and Monica, for the insight. I will look into those product next time I need epoxies.

This is the kind of information based on actual user's experience that I always look for, but all too rarely find!