Q: Where To Buy Building Materials?

[Bill in Houston]

Yes, I really should have stated that washing one's hands is NOT a recommended practice. Thanks Vekke.

[Vekke]

I would quess that cheapest place to buy those materials is one of the nearest boat building shops:
massachusetts boat builders - Google Maps

Ring few of them and see if they are willing to sell the materials. Tell them what you are building first because they like to know it has helped when I have asked materials. Usually you get the materials at least half the price. They can also give better estimation how much materials you will be needing for your whole project.

You were first building that 1:4 model and after that 1:1 model and on both cases you first make glasfibre molds/tools?

[NeilBlanchard]

Have you used Elmer's glue (white or the waterproof yellow) to do fiberglass? I am interested in this, especially if it would mean that it was biodegradable. It certainly would be easier to wash up, and is very low VOC.

[bryn]

i have not tried elmers, might be worth a few sample squares to see how it compares, as for glass, there are two main types, e-glass, and s-glass. s is a little more expensive but much stronger, the only benefit to e-glass that i can think of would be that it is clear, s glass has a slight blueish tint. kevlar would be ideal for strength and impact resistance, carbon fiber for strength and stiffness but those are both very pricey! as for polyester resin vs. epoxy. epoxy wins every time. easier to work, easier to adjust set times, better adhesion, less voc, you can thicken it, repair it if need be, just follow instructions carefully, have fun.

small boat building books from the library can be a huge benefit when making slippery shapes, and they tend to deal a lot with one off designs and lots of ways to get around the same problems. you will come across with your project.

[skyl4rk]

Originally Posted by NeilBlanchard

Hello folks,

I have asked at my local auto body shop, and they do not have a source for fiberglass. So, my question is: can you please post specific information on where to buy fiberglass building materials? In particular, I want to buy epoxy resin.

Thanks in advance.

Are there other materials that you have found useful? Please post the information for others to get them.

Raka, Inc. 772-489-4070
Get 2:1 ratio resin to hardener, it is less toxic than 4:1. For example, from the site above, a good combination would be Resin 900 Medium and Hardener 608 Medium. Fast hardener can be too fast in warm weather, and Medium cures overnight just as well as Fast does. I have used Slow with good results too, it just takes a bit longer to cure in cold weather.

Get a small postal scale that reads out in half ounces. Use the scale to weigh out the amount of resin you need, then add half that weight in hardener. The pumps are convenient but then you have little control over how much or how little epoxy you make.

Buy a bag of cheap chip brushes, a bag of tounge depressors and a bag of pint plastic containers.

Raka, Inc. 772-489-4070

You will want a few different types of fillers. Silica is the strongest but is hard to sand. Wood flour is a middle ground and usable in most areas. Microballoons (glass bubbles) are for sanding and fairing. You don't need much of each. $10 buys enough filler for a big project. At a minimum you will need silica and glass bubbles. Make sure you wear a mask while mixing fillers, the powders get in your lungs if you don't.

Raka, Inc. 772-489-4070

6 oz plain weave is pretty much a standard glass cloth for covering plywood. You could go thinner, 4 oz, for example. You can cut tape (strips of glass cloth) with a quality scissors, it is usually cheaper than buying tape.

[skyl4rk]

Originally Posted by NeilBlanchard

Okay, I have some specific questions about the various fiberglass fabrics and epoxy resins:

Fiberglass Cloth

Epoxy :*Epoxy Resins and Hardeners

For the skin on my 1/4 scale CarBEN model, what weight and type of fiberglass fabric would be best?

4oz plain weave

For the full size shell of the CarBEN EV, what weight and type of fiberglass fabric would make sense? For the bottom and the surfaces where suspension components will be attached, I am thinking that using a heavier fabric will be good.

Use plywood or hardwood buried in multiple layers of glass cloth and silica filler for hard mount points. You can use 6oz plain weave for this as well as anything else, although a biaxial or triaxial woven roving may provide more bulk and strength. I would just use plain weave until you know what you are doing and can design a special layup.


To make smooth wheel covers, or wheel strakes, or belly pan -- the same question?

Thin plywood covered with one layer of lightweight cloth, 4 oz would work.

I know I need to use epoxy resins since I am using EPS foam to build up and carve the forms; but should I use the medium set time thin epoxy, or the slow, or the fast? The outside will have the skin first, and then I'll skin the inside, as well. The inside of the hood area, the inside of the battery compartment in the floor, and the front and rear wheel wells and skirts, also will be fiberglassed.

It is very difficult to get a smooth finish when covering foam with glass cloth. I would suggest testing the following for nonstructural parts: Sand the foam to shape. Cover with clear epoxy, let cure. Spread glass bubble filler over any rough spots, sand. Paint. I don't know what EPS foam is so I may be way off on this. Plan on using a lot of glass bubbles and doing a lot of dusty, dusty sanding to get glass cloth smooth. Take anything of value out of your workshop, it will be destroyed by the dust.

Should I get the 1oz pumps? What applicators, rollers, gloves, masks, suits, etc. would you recommend?

See above, get a decent respirator with a dust filter. Get a box of disposable gloves. Tyvek arm covers are useful, I seem to get a lot of epoxy on my sleeves. Wear clothes that can be thrown away after your project is done. Always change into throwaway clothes before using epoxy or sanding epoxy/glass.

I find that a bag of 1" and 3" chip brushes covers most of my needs. I don't use rollers.

[Bill in Houston]

Originally Posted by NeilBlanchard

Have you used Elmer's glue (white or the waterproof yellow) to do fiberglass? I am interested in this, especially if it would mean that it was biodegradable. It certainly would be easier to wash up, and is very low VOC.

Does the body have to do anything more strenuous than sit in a wind tunnel?

[NeilBlanchard]

The 1/4 scale model -- no nothing harder than that. But I am also going to be starting the full size actual shell soon; and it will be fully structural.

Is there such a thing as biodegradable foam, and if so is it available in sheets? If it is otherwise similar to EPS, than that would be great!

[Bill in Houston]

if it's going to just sit in a wind tunnel, glue and glass is fine.

you could make a paper mache form to put glass on instead of foam.

i have seen biodegradable foam packing pellets. they taste like corn pops. i don't know if that stuff comes in sheets.

[NeilBlanchard]

I Googled "biodegradable foam sheets" this morning and only came up with very thin sheets: 1/8" 3/16" and 1/2". Also, lots of packing materials.

I'll keep looking.