1808 vs. 2415 stitched cloth comparison ?

Greetings,

I have found a local supplier of fiberglass materials and am considering ordering some to finish my extension bracket project. (see my thread for details, if desired)

Anyway . . . I have been using a combination of 1708 and 1808 cloths to get the desired directional strength of the fiberglass laminations. The local supplier does not list 1808 (0˚/90 biaxial), but has 2415, which I understand is a stitched woven roving & CSM combo.

Question for those in the know . . . would 2415 be a suitable replacement for 1808? or would the 'woven' aspect of 2415 be a significant difference-maker in terms of strength? I would certainly need fewer layers with the 2415, but also wondering about resin/glass density differences.

T.I.A. for any guidance

 

I don't know anything, sorry.
I do use the Vectorlam software (free from Vectorply after registering) when I have questions about this sort of thing.
I make a laminate that is as-is and another 1-2-3 that are proposed and compare them.
Below is one layer each, polyester resin.

PS On the job I first needed to use this, I ended up cutting 1708 at 45 degrees to make 1808 as my local supplier also does not carry 0/90 stitchmat. By using the calculator, I found out I was 1 layer short of making a comparable laminate to what I was replacing and that I needed some layers to be 0/90 instead of 45/-45.

 

It won't be as strong or stiff, so the equivalent strength will weigh more.

You could make it work if those things aren't critical to your design.

 

That is what I was thinking because the strands in a 'weave' are not straight. (more shaped like a sine wave). I would assume it is a way to build up bulk, since the resulting laminate is thicker.

Perhaps my best approach is to use 2415 in areas where the strength is not as critical, and 1808 where it is critical.

 

If you ask Google (AI) enough questions, you can get decent answers . . . Here is one answer that I got that makes the most sense to me . . . I asked a tensile strength comparison of the 2 cloths with vinyl ester resin.

Here is the AI summary:

"Both 1808 and 2415 fiberglass cloths are high-performance structural fabrics commonly paired with vinyl ester resin for marine and industrial applications, but they offer different tensile strengths due to their construction and weight.

• 1808 (18oz Biaxial + 3/4oz Mat): Designed for high strength, 1808 consists of 0°/90° knitted (non-crimp) biaxial fibers paired with a mat backing. Its non-crimp construction keeps the fibers straight, allowing for efficient load transfer and excellent tensile strength, particularly in the fiber directions.
• 2415 (24oz Woven Roving + 1.5oz Mat): 2415 is much heavier and generally used for rapid, thick laminate build-up. It is a "woven" material, which means the fibers have more crimp (bend) than knitted 1808, generally making them slightly less efficient in pure tensile loading compared to the same weight of non-crimp fabric.
• Tensile Strength Comparison: Because 2415 is significantly heavier (24 oz roving vs 18 oz biaxial), it will provide higher total strength per layer in a laminate. However, on a per-ounce or per-thickness basis, the 1808 (due to being non-crimp 0/90) will generally offer superior tensile strength for its weight.

Key Takeaways for Vinyl Ester Applications:

• 1808 is ideal for structural areas needing maximum strength with less weight, such as stringers, hulls, and decks.
• 2415 is better for rapid, heavy-duty buildup where bulk and stiffness are required quickly.
• Vinyl Ester increases both, providing better chemical resistance and higher bond strength (roughly 10% higher) than polyester resin.

If the goal is maximum strength-to-weight ratio, 1808 is superior. If the goal is rapid, thick, and durable buildup, 2415 is superior."

 

18 oz/yd
3/4 oz/ft = 27/4 or 6.75 oz/yd
24.75 oz/yd

24oz/yd
1.5 oz/ft = 13.5 oz/yd
= 37.5 oz/yd

37.5/24.75 = 151% the weight

Keep in mind; the resin ratio will probably be higher in the wr as well, based on simple physics of liquid filling the space.

You would only use to develop stiffness unless weight is not a concern and you wish to use up some fabric.

 

Thanks for the replies folks. . . .

I'll use the 2415 in areas where I want to bulk up the thickness and the strength would be adequate. Other areas will be 1808.