In class we are making kitchen appliances out of blue foam for a modelmaking class and I am having a blast! It’s a difficult medium to work with, but it’s still fun seeing the end result from a big blob of blue foam.
My question is: sometimes when using Super 77 (which is what my professor recommends) to bond together pieces of 2’’ blue foam, I have had problems with the adhesive eating away at the blue foam and creating a mess internally. The blue foam pieces stacked together look seamless all around, right… until I start cutting into it and then I see that there are craters, from the adhesive eating through the material. Is the problem that I used too much of it? Any tips? For most guys in my class, it works well, but for me, it hasn’t. Don’t know what I may be doing wrong. I do recollect using a lot of it on the foam pieces, thinking that more is better.
Use less of it. Laying a thick wet coat gives the adhesive time to eat the foam. Try 2 thin, light coats on each surface. Make sure to let the adhesive dry between coats and before you assemble the foam pieces.
Thanks PDog. That was a quick reply. I will try that out tomorrow and give an update.
You can also try other glues. I used to use gorilla glue, that won’t eat blue foam at all.
gorilla glue can be difficult from the stand point of its a different density than the bluefoam which can present problems when you are sanding.
Just another question: I know that blue foam is not the type of stuff to be making permanent, long-lasting models out of and is usually considered “mock up” material, but I really like this one model I made (as it is my first) and would like it to be a color other than blue. Is it possible to paint it with acrylic paint or gesso? I know stronger solvents and heavy paints can also make it melt, but what about water based?
Water-based is fine.
It has been a real long time since I worked with blue foam, but I do recall there being a water-based spray paint that didn’t eat the foam. I am sorry but I have no recollection of the brand name.
If you are careful, you can seal the model with gesso and that will protect it from solvent-based spray paints. I will warn you this is a very high-risk option. The tiniest gap in the gesso can lead to catastrophy and so can putting down the paint too thick. Take a lot of pictures of the existing model before considering this.
coat it with wall spackle and you can paint it with anything.