what is the difference between these 2 biaxle clothes?

lime4x4

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DBM 1708 Knytex Biaxial from uscomposites
and
Fiberglass Biaxial Cloth is a #1708 E-glass Biaxial (+/-45 degree) Cloth with 3/4 oz mat backing. From jamestown

The price difference is about 30 bucks plus shipping is alot cheaper from jamestown. I've used the 1708 from uscomposites and i liked it. But like i said for 25 yards it's 30 bucks cheaper at jamestown. Plus jamestown only charges me around 15 bucks for shipping while uscomposites charges around 40 bucks
 

jdsgrog

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Re: what is the difference between these 2 biaxle clothes?

In all honesty, I don't see that much difference. I've bought other stuff from Jamestown and they're a good company. The difference in cost may simply be a matter of branding for all we know. I'd probably buy some from James town and see how their fiberglass 1708 is. Maybe others with experience using different biaxial cloths can chime in.
 

ondarvr

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Re: what is the difference between these 2 biaxle clothes?

Possibly a different brand of glass, but the product discription is the same.
 

erikgreen

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Re: what is the difference between these 2 biaxle clothes?

Knytex is a brand or manufacturer, by the way.

If the bias on the two cloths is the same (0/90 or 45/45 or whatever) then the only thing different between the two might be the coating on the glass, but as long as it's compatible with epoxy it doesn't matter too much.

Given that the stuff usually sells for about $10 a yard, I'm not too surprised that it's $30 cheaper for that much fabric. Prices for glass vary widely by seller, depending on their volume and how much financial trouble they're in :)

FYI, if you're using epoxy you can skip the mat and just get DB1700.. essentially the same strength but much less resin required..

Erik
 

lime4x4

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Re: what is the difference between these 2 biaxle clothes?

i'm using epoxy. I went with the mat for added strength. Actually using the epoxy from uscomposites it wets out rather easily.
 

erikgreen

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Re: what is the difference between these 2 biaxle clothes?

Yeah, wetting out isn't a huge issue... it's the fact that it takes extra epoxy to wet the mat as compared to the cloth without mat.

Compared to the biax fibers, the mat adds maybe 10% of their strength or less.. it's that much weaker because the fibers aren't aligned with each other. Yes, that means the fibers provide strength in all directions, but it's only a very small amount.

A lot of "experienced" fiberglass pros seem to misremember the properties of mat, specifically I've heard it called "the strongest fiberglass" and "better than anything else for reinforcing".

I think they remember "strongest" because when they find a part of a boat that needs more strength usually mat gets added.. it's a cheap fix in a way.. the added thickness adds lots of strength and stiffness compared to the thinner glass. But adding the same thickness of fabric or biax would be much, much stronger.

Mat is mainly used with poly resin because A) It's cheap and B) It's needed to adhere polyester resin to hard surfaces. If you use epoxy there's no reason to use mat except perhaps to prevent print-through of a pattern under a visible surface. Or maybe if you have a lot of tight curves to fill, like in a mold.

If you want more strength, it's much cheaper to add more fabric or biax than more mat... the mat itself may be cheaper, but it absorbs a lot of expensive epoxy resin, and adds very little strength.

Erik
 

lime4x4

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Re: what is the difference between these 2 biaxle clothes?

any ideas where to get db1700? uscomposites only has 1708
 

erikgreen

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Re: what is the difference between these 2 biaxle clothes?

I get mine from boatbuilder central, aka Bateau.com. Best price I've found for it around, about $8.75 a yard.

Disclaimer: I'm not affiliated with Bateau, just a happy customer.

Erik
 

lime4x4

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Re: what is the difference between these 2 biaxle clothes?

ouch us composites has the 1708 for 6.05 a yard
 

erikgreen

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Re: what is the difference between these 2 biaxle clothes?

ouch us composites has the 1708 for 6.05 a yard

That's for the 38 inch width. The stuff from Bateau is 50 inches, like the stuff from US Composites that costs $8.50 a yard. If you buy from Bateau in 10 yard increments it's $9.00 a yard (I typoed earlier, was supposed to be $9.75 not 8)

Really, depending on source it might be cheaper to use the 1708. Personally I like saving the effort and resin involved in saturating the mat, but if you can get 1708 a lot cheaper (50 cents a yard isn't really a lot) then use it.

/shrug

Erik
 
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