I’m taking time over the next year learning about a lot of topics to hopefully have the satisfaction of building my own proton pack mostly myself from scratch.
I saw a few posts on the difficulties in fiberglassing and came across a listing of fiberglass cloth. Fiberglass Cloth
There’s apparently a ton of different types! Anyone have any thoughts and/or suggestions about type of fiberglass to use, e.g pros/cons for top choices and a personal opinion as to a final verdict of which to use?
My advice for fiber glass is to look at “cat hair” type which litterally looks like clumps of hair but when mixed with resin makes a great filler and builder. As far as cloth types, it really depends on what your using it for. I have never worked with molds before but if your doing an overlay on top of something like boxes all I can say is be generous with the resin. If not the cloth likes to raise off of curved areas. PITA!
It depends on the application. If your doing smooth gentle curves and a lot of flat surfaces, such as a boat hull, use the cloth type. If you have sharper edges and varying details, like a pack, use mat. You can also use loose fibers like I did for hard to reach areas, but it leaves little jaggies inside that need to be grinded away. If using the mat, its best to pre cut all your pieces so you can lay them in the mold easier. Try to limit you cuts though. The more individual cut pieces you have, the less structurally sound it will be. The “cat hair” type I’ve never used but it sound pretty neat. It would be alot easier to make a hair putty and spread it on. Good luck with your project !
Actually this is the worst thing you can do and totally against good fiberglass technique…
The optimal resin to fiberglass ratio by weight is about 40:60 meaning for every 40 grams of resin you use 60 grams of glass… This is the ratio you should be aiming for even if you don’t get there… Fiberglass gets it’s strength from the glass not the resin, in fact fiberglass resin is honestly horribly ■■■■ poor in strength and brittle…
As for the type of glass to use, lots of schools on that but in general…
POOR: milled fibers, small flocking or glass spheres
GOOD: chopped strands, can be in the BETTER category if done right but almost always has too high of a resin to glass ratio and/or filler is used to build more body
BETTER: overlapping pieces of cloth or mat, if using mat care should be taken to pull the pieces apart giving a ‘fingered’ edge and overlap generously
BEST: Woven cloth in a single sheet
OPTIMUM: Woven cloth in a single sheet, carefully laid down in perfect geometric pattern and cured under pressure… This is most obvious on carbon fiber layups, where the fabric pattern is ‘perfect’ and continuous and it’s a perfect lamination with no obvious inconsistencies top or bottom of the layup…
Most commercial glass is in the GOOD/BETTER range… The BEST/OPTIMUM range is generally high end performance stuff or stuff that will experience extreme forces like airplanes or even surf boards…
Exactly. Too much resin doesn’t help at all. You just need enough for the cloth to soak it up, leaving no “white” areas.
Also, you don’t have to glass the entire shell at once, you can work sections at a time which can make things easier if you’re not used to working with larger amounts of material.
There is a difference between “being generous” (ie; making sure the cloth is evenly wetted by they resin and not spotty) and just dumping a glob on there and spreading it like pancake batter. That was taken too far out of context.
In addition to looking over this thread I watched a “how to mold fiberglass” video on YouTube that looks like it’s using the chopped strand mat fiberglass. I also did a quick read on Venkman71’s molding tutorial, but couldn’t make out what he’s using for the pack itself (The silicone mold cover looks like it’s made of chopped strand mat.)
I looked over the prices on the first site I turned up and it doesn’t look horribly expensive for the fiberglass regardless of the type… I’m inclined to spend a few extra dollars on the woven cloth and apply it in a single sheet BUT reading through the comments there seem to be some differing opinions about using that type on a pack shell, or I just need to be more specific on what my goal is. I’d like to do something similar to what Venkman71 describes in his casting tutorial (only tutorial I found really, unless someone feels there is a better approach).
I see stuff anywhere from 3 oz. - 40 oz. weight and would assume the lighter stuff is easier to mold to something like the gearbox and here’s where I’ve landed so far… woven fiberglass cloth
My biggest concern is whether it’s reasonable to attempt using a single sheet of woven cloth on something the size/dimension and detail of a proton pack. The gear box has some decent detail (unlike a boat hull) and there are steep vertical drops around it as well. I plan on practicing on some small ■■■■ laying around the house but before I make an expensive purchase, anyone think this would be an issue? How many layers are “typical” for something having the size/dimensions and detail of a proton pack?
Um laying one full piece of glass into the mold is going to be near impossible. There are too many different geometrical shapes as well as different depths to worry about. If I read that correctly? To be honest as far as layers, I stick by one. As I’ve said before were not building bullet proof packs or a boat hull. In this application more than one layer seems over kill IMO.
Thanks for all the great responses. It’s probably going to be a little while before I’m able to start working with the stuff but I’ll be sure to post my thoughts/headaches/progress along the way.