In this project I decided to build Thor’s hammer Mjolnir light enough to use for self defence or as a real world weapon. For me there was only one material choice, fiberglass. The trick was to cast it in a big enough block.
Thors hammer replica dimensions
The replica Dark world Mjolnir that I based my full metal Thors hammer on, had these basic dimensions of 220mm on the longest front to rear face, and 140mm on all other sides. For this new fibreglass composite build I went just slightly larger just to give it a slightly more cartoony look. We have used fibreglass before for a superhero build and that can be found in my Captain America shield project.
The fiberglass handle was cut from a ‘Kangs’ fibreglass post hole digger, it just happened to be 32mm across which was perfect, especially as I found some solvent weld pipe with an internal dimension of 32mm to make the handle grips.
Thors hammer mold
The mould was made from standard 6″ or 150mm melamine type shelving, it’s very cheap and would resist the resin sticking to it, especially if polished with wax. The two fillet angles needed are a simple 45 degree fillet and a slightly more difficult sharp right angle made by making a cut of 60˚ and 30˚. The fillets stick very well with the cheapest silicone sealant you can find. By sticking them to the sides and bottom of the mould only, this left the end caps free to be removed after casting making the hammer easier to remove without damaging the mold.
Mold release wax was used to polish the internal melamine and any gaps between the fillets and also the side walls of the mold I filled with wax. I did hear that vaseline can work as a substitute, but why bother when you already have wax? So that’s what I did.
For the resin I used the cheapest Polyester fibreglass resin I could get, which was actually a re-blend (cheaper than regular resin), and I decided to use loose fiberglass chopped strand rather than a weave or a mat. This decision was purely for speed of mixing and laying. I could have used CSM (chopped strand mat) or a woven fabric, but this would have involved a lot of cutting, although technically it would result in a stronger build.
The above project is aimed at adults for education and entertainment purposes only, not to replicate. Anyone doing so takes full responsibility for their own actions.