What fibre and resin are you using?
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Mix of Sergé Carbon fiber 3k + fiberglass
This kind
I’m planning 0-90-0 layup
Red dots where I need to cut or pierce 
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Oh sorry I didn’t see this part, it’s SR Glass One epoxy from Sicomin, slow cure time (last time I tried it I had to let dry for 48 hours in vacuum)
Dude if i were you i’d be practising with glass of similar weight/composition before playing with carbon. That shit is expensive.
I would recommend getting on the Easy Composites youtube channel and watching as much as possible. They have some excellent videos on many different methods, all very well put together and articulated.
My best advice would be to try and shape the fabric as best as you can while it’s dry before you start applying resin. Pinching the fabric on hard corners can help it to hold it’s shape, and very small amounts of spray adhesive can help too. I’ve never used it, but apparently ‘Aerofix 3’ is the bees knees
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Well tbh I had a killer discount and paid like 13 bucks for a bit more than 1 square meter of CF, I appreciate your warning tho!
I did test the process on printed test sticks before (wanted to know what kind of printed core was better when sandwiched in carbon) with a bump on top of each stick, the fold wasn’t great on top and caused delamination on the first iterations.
I could still cut the edges to keep laid faces only but it’ll be ugly 
Ah quick note, don’t bother trying to wrap TPU in CF, it’s gives you a thing with useless mechanical properties 
it’s not rigid nor soft anymore that’s a weird result.
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Sounds like a plan, will try it! Thanks for the pointers 
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You’re courageous, i’ll give you that i’ve been playing with this shit for 2 yrs now and still don’t have the balls to try complex shapes with carbon.
Good luck!
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I have a permanent container (with lid) of paint thinner where my brushes live. They don’t degrade, and no clean up required.
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Nah. Chip brush in the bin after use
Fabric application tip - practice. I’m not an expert (edit - also can’t type on my phone for shit) but my 2c. If you’re doing a regular layup try let previous epoxy coat tack before applying fabric. Then when you apply fabric, it won’t move after pressed onto the tacky resin. Then once it’s stuck to the tacky resin, let that cure before more resin. If you go another coat straight away, the fabric can lose adhesion and shift round and pull out of corners etc. good luck
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Great stuff, thanks man.
Acetone cleans and thins polyester resin real quick
Even if one uses the chip brushes for resin this can be very useful for painting and other stuff.
What exactly are those two bottles in the picture and the other thing in the middle?
Haha, no idea - it was the first google image result. The glass mason jars are showing the brush cleaning in one and the clean jar w/ paint thinner in the other.
It’s from this link:
They don’t explain the mystery “Brush and Roller Cleaner”
Edit: you made me curious so i did some quick digging - looks like it holds the roller/brush and spins it
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Cheap fiberglass enclosure with no special equipment
I needed custom shaped big volume enclosure for one of my decks, because available enclosures were either too small or bad fit. So I have decided to try working with fiberglass for the first time. But at the same time I didn’t want to invest a lot into it, buying special tools and special materials for mold making. Tips on this forum were super useful, so I want to share my experience, maybe it will help someone.
Mold
I have decided for positive single use mold. Enclosures made out of positive mold are generally not as good looking, but it’s easier to make inner dimensions correct for your electronics. I cut the inside dimensions of enclosure out of 10mm and 20mm polystyrene sheets which I hot-glued together. Then I cut chamfer around the corners, so the enclosure is not as stressed on corners. For cutting the polystyrene you need sharp blade.
I wrapped the whole thing with brown packing tape. I also wrapped whole deck, since I use the deck itself as part of the mold. I attached the polystyrene block to the deck with hotglue and covered the gaps with more packing tape. Brown tape doesn’t stick to fiberglass and doesn’t leave mess like clear tape.
Laminating
For laminating I have used 3 layers of 340gms fiberglass weave cloth and around 400ml of resin. I first put cloth, then resin, so I haven’t started with resin on the mold. First time the resin turned into gel when I started to work on first layer, so you have to work fast and prepare everything before putting activator into resin. Instead of brush and roller I used piece of wood and piece of cloth, worked fine.
After the cloth and resin was layed down, I used cheap vacuum bag for clothes to vacuum it. Once again, so special equipment like epoxy vacuum pump, I just used household vacuum cleaner. But I used piece of cloth on the vent to protect it so I don’t suck the resin accidentally. The vacuum bag can be reused.
And it worked good enough. It’s smooth from the outside. When the enclosure was still attached, I drilled holes booth through the enclosure end deck so I have them aligned well.
The polystyrene inside got eaten up. But it must have happened during curing from the vapors because the inside of the enclosure has good correct shape. Kinda rough, but no deformations from melted polystyrene.
The packaging tape left some marks on places there it was in contact with the epoxy. It doesn’t usually leave big marks. Nevertheless it protected deck well and didn’t stick to epoxy. Cleaning was easy with some alcohol.
Post processing
I used dremel to cut the enclosure corners. Not as easy as I thought, but doable. I used one of those FFP2 respirators that everyone nowadays have everywhere, but this is not a good protection since the rubber bands on the respirator are not pressing it enough on my face and there are gaps. I felt like shit in the evening from the fiberglass dust that I have inhaled.
There were some holes in the enclosure, so I had to use some extra epoxy and filler to fix them. Didn’t use enough resin at some places.
I then used rattle can spray paint, antracite gray color. At this moment the imprefections really showed up. The surface is not as nice as I originally thought and I could have play more with the filler. But functionality is more important for me than aesthetics, so it’s ok.
I used 10mm self-adhesive foam as gasket and 3mm art&craft foam as padding for the battery. For cutting holes into the foam gasket I used metal drill bit which cut the holed in the foam with no problem.
Conclusion
So the enclosure is ready. I mount it to the deck using M5 hardware, same hardware that I use for mounting trucks. This build is not yet finished, so it’s not properly tested yet, but I will write some of my thoughts from building the enclosure:
- Fiberglass enclosure can be made without special equipment for low price. It won’t look as good, but it will be functional.
- My bill of cost was €16 for 1liter of resin and 3m^2 fiberglass cloth, 4€ for foam padding and gasket, €1.50 for the vacuum bag, €1.50 for polystyrene. I also used packing tape, sandpaper, filler and rattle can, but I had these stuff already at some, but it’s nothing too expensive. I believe that the material I have bought would be enough for two enclosures if I didn’t waste some material by making mistakes (working slow with expoxy resin).
- Often time I read here that making your enclosures is not worth financially. Despite my total cost was low, I have to agree with this. It’s not amout the material cost, but about time. I have spend so many hours on this. Financially it would be worth it just work overtime and then buy premade enclosure. But DIY enclosure has still the benefit that I was able to achieve the desired shape/volume. And I have learned so much working with epoxy.
- Polystyrene is fine for the mold, but next time I would use two or three layers of packing tape instead of only one layer so it doesn’t get eaten up as much.
- Three layers of 340gsm fabric is not as much. The fabric looks thick, but the final enclosure is not as thick as I would have guessed. Next time I will use like five to eight layers of fabric, probably combine it with finer 100gsm weave as well. But still the enclosure is strong enough.
- Also next time I will prepare more resin, because at some places there was not enough resin and it created holes that later had to be fixed.
- Vacuum bagging is important. Without it the corners wouldn’t be as good. But the good thing is that cheap vacuum bag for clothes and household vacuum cleaner can be used.
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Nice work dude! Weird that the epoxy ate the foam, i wouldn’t have thought it would do that. Polyester would for sure tho.
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It must have been the curing vapours that ate it. I was surprised as well. But thankfully that shape remained fine.
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Do you have a photo of the label for your resin? It looks 100% like polyester resin the way it ate the poly?
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Really nice tutorial, regarding resin for the first time I suggest taking epoxy resin and hardener combination that turns jelly after ~120min, that way you will have enough time to work it arround properly, fill in/push out all the bubbles that will form near fillets. Also don’t mix up too big of a batches. I used small drinking cups from coffe wending machines and mixed about 1/3rd 1/4th of a cup at the time (you can use kitchen scales for propper proportions).
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Yeah, 120min epoxy is a way to go for a beginner. I personally picked up random epoxy for laminating. The datasheet said 40min to turn into jelly, but first time it turned into jelly under 20min. Maybe I have put too much hardener into it or it might have been too hot during summer day. On second try I knew I have to work fast, but if I was doing like 8 layers I would definitely not be able to do it on one go.
When mixing epoxy in multiple batches, is it ok if lower layers of fiberglass are jelly and you put new layers with freshly mixed epoxy on top of that? Will it hold well together?
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