Hi South London Makerspace hivebrain,
I’m currently looking to make some waterproof electronics cases with textiles. From what I’ve read, my best bet is to use TPU coated fabrics that I can bond using a leatherworking iron or other heat sealing tools.
I have a few questions:
if I get TPU coated fabrics, are they ok to laser cut? I’ve seen some information online saying it should be ok but I wanted to check
does anyone know any suppliers for TPU coated fabrics in the UK? I’m struggling (https://www.profabrics.co.uk/ only seems to have PU coated fabrics which I can’t get a good seal with, https://www.adventurexpert.com are an option but the minimum order is €160 for the UK, https://www.extremtextil.de/ also seems like an option but outside of the UK)
do we have any equipment for heat sealing fabrics? I have a leatherworking iron but would be curious to try out alternatives
As an alternative, have you looked at using non-coated fabrics, sew it up into the shape that you want and then apply a coating to it yourself? The coating gets into the seams and seals it up.
Very different use case, but I made a skin on frame kayak that way a few years ago. I used some “ballistic nylon uncoated” fabric from profabrics. I can’t remember or find what coating I used, but you want something whose stretch matches your fabric (and not eg. epoxy which cures rigid).
I had some success bonding together PVC tarps as I needed a custom size and shape.
I used a mini heat press iron normally used for HTV vinyl on the highest setting with greaseproof paper between surfaces I didn’t want sticking together (such as the iron and the fabric and the “pocket” area of the fabric)
You could likely try with the large heat press in textiles but you will definitely need a protective layer to stop the fabric potentially melting onto the heat plate and it may potentially release hazardous fumes.
I agree with Paul re coatings;
I’m currently making some waterproof fabric pouches and testing out Odicoat Waterproof Fabric Coating
I have a load of experience in this field - Whilst TPU is excellent for waterproofing, its a nightmare to work with and also not laser safe at SLMS. I’d advise against working with it in the space as it can get a bit noxious and stinky when working with it and an iron etc.
Its also worth noting never ever put any PVC in the laser.
Do the pouches need to be submergible? If not id recommend using a PU coated nylon from pro fabrics and then its about how you design the pouch to maximise water ingress resistance.
You can also get seam sealing tapes from pro fabrics which is easy enough to work with.
I also order from adventure expert alot and have an order I need to do soon.
If you’re around on thursday ill be at the space all day and happy to discuss with you further.
Hi All, thanks so much for the helpful responses! @plietar I hadn’t considered non-coated fabrics and then coating myself. I will try this out - thanks! @LouLou thanks also for the suggestion of the coatings and film. I’ll have a look into these. I am hesitant to use PVC as I’ve read it releases harmful gasses when heated @charlesmein thats really good to know about TPU on the laser - I’ll avoid this and will also avoid PVC
I do have some seam sealing tape from profabrics which I’ll try out some PU-coated fabric I have. I’m not sure how to use it yet but I’ll look for some guides and videos
My pouches don’t need to be submersible but would ideally be able to stay outside for extended periods of time (multiple days to weeks)
It would be great to discuss this more as I build up a workflow around waterproof fabrics. I am working on thursday but plan to be in the space after work (from 6ish) so if you’re around I’ll come say hi
also doing an adventure expert order together would be great!
thanks all
For rainproofing in my experience I’ve found the shape is also a key element, so having the top shaped to have the water run off as opposed to pool, and the bottom layer being as waterproof and seamless as possible (pressure sustained over time like from the ground pressing into it is when ive had most failures, you can sometimes even get away with no seam sealing if you’re clever about where the rain will be directed)
