# Epoxy and Fiberglass Spreadsheet

#### blackbrandt

##### That Darn College Student
Messing around a bit and made this Excel spreadsheet to calculate the amount of glass and epoxy you'll need for a project, as well as the ratio you need.

Let me know if you see anything that needs to be fixed, but I'm 99% sure it's correct. Feel free to use as you wish.

View attachment Epoxy and Glass Calculator.xlsx

#### Woody's Workshop

##### Well-Known Member
TRF Supporter
Thanks Blackbrandt.
Could ya do me a favor?
Save it in the old format that my old outdated Office 2000 can read please?
Thanks.

Oh, and the read only doesn't show anything.

#### BDB

##### Absent Minded Professor
This is fantastic. I'm hoping to glass my first set of tubes this weekend. Thanks.

#### dr wogz

##### Fly caster
Well, don't you apply epoxy to fiberglass sheet and spread?!?
or is it apply Epoxy and spread sheets of fiberglass..

#### blackbrandt

##### That Darn College Student
Thanks Blackbrandt.
Could ya do me a favor?
Save it in the old format that my old outdated Office 2000 can read please?
Thanks.

Oh, and the read only doesn't show anything.

Try this. Should work.

Also, the spreadsheet is 2 sheets, I forgot to mention. Information on first sheet, calculation on second.

View attachment Epoxy and Glass Calculator - Copy.xls

#### manixFan

##### Not a rocket scientist
Try this. Should work.

Also, the spreadsheet is 2 sheets, I forgot to mention. Information on first sheet, calculation on second.
Very interesting and useful. However with a little bit more work I think it could be even better:

* put in your assumptions on the first sheet so the user knows what Epoxy system and coverage your calculations are based on
for example - how much epoxy per square foot/glass weight do you use in your calculation?
* allow the user to input an overlap amount for the wrap
* output epoxy values in metric as well
* allow user to modify the waste factor for epoxy (I see you are using the formula that West System uses which provides for a 15% waste factor)
* using the West formula I get that the volume (by oz) should be 7.33oz yet you put that as the weight and have a different amount by volume. Might double-check that calculation

More importantly West systems has the following guidelines:

"Dispensing without Mini Pumps (Weight/volume measure) - To measure 105 Resin and 205 or 206 Hardener by weight or volume, combine five parts resin with one part hardener. To measure 105 Resin and 207 or 209 Hardener by volume, combine three parts resin with one part hardener (by weight, 3.5 parts resin-1 part hardener)." So the ratios vary by that hardener used.

But even as is it's a great resource that folks can use to get started. I was able to modify it very easily to get what I wanted.

Tony

#### blackbrandt

##### That Darn College Student
I go off of my normal calculations:
US Composites 3:1 resin, weight of 9 pounds per gallon.
Equal amounts by weight of cloth and mixed epoxy.

I'll add an overlap amount in the next revision.

#### manixFan

##### Not a rocket scientist
I go off of my normal calculations:
US Composites 3:1 resin, weight of 9 pounds per gallon.
Equal amounts by weight of cloth and mixed epoxy.

I'll add an overlap amount in the next revision.
So there are the following possible mix ratios by volume then:

2:1 - System Three (which I've used for 15 years)
3:1 West Systems resin and some hardeners (probably the most popular brand) and US Composites
5:1 West Systems resin and some hardeners

West System 105 resin and 205 or 206 hardener it's 5:1 by volume or weight.
West System 105 resin and 207 or 209 hardener it's 3:1 by volume but 3.5:1 by weight.

System Three is 2:1 by volume but 2.27:1 by weight.

So to give accurate answers the formulas need to be tweaked for the particular epoxy for each user.

So if you made an input field where users could enter their own values it would be much more universal. I realize this probably wasn't your goal but it's a really great idea and very useful. I had always scratched it out and it never occurred to me to make a spreadsheet for it. I like your way a lot better.

Thanks,

Tony

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