I have been offered some heavy biaxial cloth (600 g per m)and was wondering if it is good to use with infusion.It is +/- 45 degree stitched construction.Thought it would be good for the lower layers of hoods or anything with not too curved construction as it is quite heavy.Just asking as I have never worked with biaxial before.Can also get triaxial the same weight.What one would be best.Remember reading of someone having problems infusing uni type cloths?
Actually, these fabrics (not cloth) are great for infusion and not very good for wet lay up.
Most of them flow very well and are quite drapeable.
90% of the material we use for infusion is stitched, but mainly carbon fiber. Just the same, fiberglass stitched is a lot better than woven though and produces stiffer parts.
Triaxial would be better due to the fiber orintation and the easy of layup. Are you talking glass or carbon? Either way, make sure you have lots of delay line if carbon, on your vent side. Carbon tows are hard to infuse INTO…while the part may seem to be infused, the tow itself might only be partially saturated. I get to play with a 23ozyd2 carbon braid, and will have to modify my infusion to get it fully wet.
Glass fibers are larger, so it might be easier and you dont have to worry.
As for the stitched vs. woven…it will be slower to infuse. Just do tests and see what you get. But it will def. be stronger than woven fiber any day!
FYI, a +/- 45 is a Double Bias, not a Biaxial. The letter “x” in the word biaxial causes many to get these confused.
The thickness/weight of the fabric in itself does not indicate whether it will allow resin to flow properly or not. I have seen very thick fabrics flow poorly while very thin fabrics flowed much better. I have also seen just the opposite.
Sorry for the short comments. I am trying to avoid preaching to the choir. 
Hmm…
If 45/45 is double bias, what is biaxial?
I’ve used rolls and rolls of 1708 and 1700 with no mat backer, and always thought it to be a biaxial.
Zach
We call 0/90 stiched biaxial
It is just a matter of definition, and manufacturers of the stuff make a mess of it. So what I do is always specify the orientation (0/90 or +/-45, or biax090 and biax45) in which case there is never doubt on what I mean.
As for infusion: biax45 on its own can be hard to infuse, but with an infusion mesh it works great. Smaller lengths are possible without mesh as well.
And 600 grams is medium weight. I can have it produced up to 2400 gr/m2, and quadrax even up to 3600 gr/m2
A Biaxial is a 0/90 with the yarns running in the Warp (0) and Weft (90) directions. Two of the USA producers designate these as…CD1800 or LT1800 (18 oz 0/90 with no mat), CDM1810 or LTM1808 (with 1 oz mat), CDM1815 or LTM1815 (1.5 oz mat), CD2400 or LT2400 (24 oz 0/90 with no mat), CDM2410 or LTM2408 (with 1 oz mat), CDM2415 or LTM2415 (with 1.5 oz mat)
Whereas a Double Bias is a +/- 45 and is typically designated as X1700 or BX1700 (17 oz 45/45 with no mat), XM1708 or BXM1708 (with 1 oz mat), XM2415 or BXM2415 (with 1.5 oz mat)
Add another yarn in either the 0 or the 90 degree orientation of a Double Bias and you have a Triaxial. (the nasty little “x” works better in the word triaxial) And if you add both a 0 and a 90 yarn to a Double Bias and you have a Quadraxial.
None of these fabrics have to be balanced. For larger projects like windmill blades, you may have a CDM5610 which could have 36 oz in the warp “0” direction but only 20 oz in the weft (90) direction.
If a project is going to use hundreds of thousands of pounds of fabric, the producer will customize the fabric to put the heaviest of the yarns in the direction that will carry most of the dynamic load in the finished part.
I’ve been selling this stuff for over thirty years and new fiberglass fabrics come out quite often. Especially fabrics that help resin flow better in a resin infusion process.
With infused Wind Energy parts becoming in such demand, we are seeing so many hybrids now that are made using a flow media product either stitched to or sandwiched between a generic fiberglass knit.
Herman, great idea to specify the orientation of the yarn and even the weight of the mat if applicable. This will eliminate the chance of a misunderstanding due to the possible differences in terminology.
Hi Glassmaster,
Which producer do you represent? I work with Selcom in Italy for the most. Only if I need Lloyds approved multiaxials, I revert to Formax in the UK.
Both companies are run by the most friendly people.
Hi Glassmaster,
Which producer do you represent? I work with Selcom in Italy for the most. Only if I need Lloyds approved multiaxials, I revert to Formax in the UK.
Both companies are run by the most friendly people.
If you are in the US I like COFAB. They do not make a 45/45 but their 0/90 infuses well and you can elliminate the flow media for many projects. My experience is with their A112 0-90 which is 12oz/yard. Pricing is by the pound (inexpensive, closer to woven roving than cloth by far) and they had 24" to 74" widths last time I purchased.
I was trying to find a reinforcement with good flow because my hull ends were so slim in an outrigger mold that the flow media would not fit. Connie sent me samples which not only infused well but were almost void free. My big complaint about stitched fabric had been the quality control compared to woven. With a thick laminate it would not matter but a lightweight rowing or paddling craft with two or three layers of reinforcement total will not tolerate voids which seem quite common in many stitched fabrics I have used.
I would be very interested in a stitched carbon or kevlar in 0/90 or 45/45 that is void free, or almost, If anyone has access 
Jim
It is a bit stupid to send things over the pond, but it does not seem to be a big problem.
Perhaps try Vectorply.
Also, infuse at maximum vacuum level, that helps.
Herman,
I forget that we are usually speaking of voids with infusion in regard to the resin side (I am good their for now). The voids I am referring to are yarns stitched together with one missing every several inches, or stitched with yarns not parallel. Weak spots in a thin laminate also no where to hide in a skin finish (no paint, no gel coat). Vectorply sent me 12" by 12" samples of 0/90 and 45/45. I e-mailed them about voids in their samples and if that was typical. I received no response and did not pursue it further. I can usually run 18’ or 6 meters of Cofab’s 12 oz/yard 0/90 (A112) with no voids; the intact length I currently need for my main hulls. I wish Cofab would start stitching carbon or Kevlar but they could not justify the set up by the small quantities I purchase.
Jim
The only option is to find another multiaxial producer on your side of the pond, which is small enough to do specials… JB Martin perhaps?
Thanks Herman, I will check into them. Here is a question I bet you will have an opinion on and its not far off topic. Large sections of my light outrigger hulls are two layers of Kevlar or carbon cloth and one layer of 0/90. I would like to use 45/45 for its tortional contribution to the hulls instead of 0/90 but am concerned that one layer would give an unbalanced laminate schedule, am I being to fussy? Two layers could be done balanced but I do not want the extra weight. This also depends on my finding a 45/45 I am happy with:)