As I’m renovating a £360 eBay 1967 Gull I didn’t want to spend a fortune on fancy epoxy and filler. So tried a few cheaper alternatives.
For resin I used Sicomin SR5550 Epoxy Laminating Resin with the slow hardener SR5503. At £30 for 1.29kg from MB Fibreglass it was a good saving vs the major marine brands.

I had used Sicomin back in the 1980s to build my foam sandwich proa and that came out light and nothing ever broke so it wasn’t a total gamble.
One slight worry was the 100:29 by weight ratio. The data sheets gave no by volume but a bit of digging and I found a French website that said 3:1 by volume – fantastic
I mix small batches using 10ml syringes so this was perfect. I have laminated glass, carbon and Kevlar as part of the restoration and bonded with some West Colloidal Silica I had. All these applications have gone well, seam as strong as anything but only time will tell
For filler as there is a lot of cosmetic damage stuff to do I just wanted to use polyester car body filler. So readily available was Big Boy ultra fine body filler £6.19 for 250g from Toolstation

I was impressed to begin with as the catalyst came as a good amount in a proper tube rather than those foil sachets that always run out. The filler mixed easily into a nice creamy consistency, I probably would like it a bit stuffer for the vertical surfaces but it goes on well.
As I’m allowing 24hours before sanding I probably use a like less catalyst than directed and an amount a little more than a teaspoon gives me about five minutes of working time. It does do an odd thing in that when it goes off it goes from workable to unworkable in about twenty seconds.
On the positive / negative it sticks like nothing on the metal tools I use as palettes and spreaders. No big issue, I use packing tape to create a removable cover. Hopefully the bodes well for how well it’s stuck to the boat 🤞

Once set it sands very nicely, it is probably a bit soft for high wear areas but works for my application.
Thanks for the heads up on the epoxy. I get through a lot, either West or from Plymouth Fibreglass. I use the cheaper of the two for filleting and glueing, so an even cheaper one could be most useful.
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