Dry Roving

Does anyone have a better way to loosen the strands of roving that refuse to wet out? Currently I just beat the piss out of ‘em with the lam roller. This takes a lot of time and on big parts it can be a real pain.

I typically don’t use roving because of its poor shape holding ability. Most of time I work alone and as I am sure you know roving needs a few hands to achieve perfect placement. However if it weren’t for the dry streaks roving would be a joy to use in certain applications.

Well I won’t hold my breath but I do hope there is an easy solution ....

Thanks for reading.

 

What resin are you laminating with and at what temperatures?

 

Most roving will wet out completely with polyester, almost becoming invisible.

 

Maybe triax or bi ax may be more suitable for tight areas, the rovings certainly will wet out though, but not when it is tight

 

The reason for strands not weting out is it will have binder on it and the desolving of the binder takes time so use slow gelling resins ! just needs time to soak and disolve !!

or

get some stitiched double bias the same weight , it has no binder and drapes much better than any woven !! wets out with any sort of resin !!

 

Gonzo, I glass in temperatures anywhere from 35 to 70 deg. Mostly on the lower half of that scale 40-50 deg. almost always with polyester. I don’t recall the temp making any noticeable difference, but my memory is not that good. I do see what your getting at though and it would seem to make sense. Next time I use some roving I'll warm the resin up and see if that helps.

Tunnels, I had a suspicion that it may be some kind of binder. It seems like they might need to recalibrate the machine that applies it because it’s only a couple of strands every three or four feet. I wonder if a different supplier might help this problem? ....

Ps. this is an age old issue not something I just ran into.

 

The binder things is old hat !!
There shouldnt be any binder used in woven but the older matts used it to hold the fibres when they flattened the strings . Me i would simply switch to using double bias of the same weight ! all stitched and no binders at all !! even if it has CSM on the back its stitched on ! no binder !!!.
Wets really quickly and drapes much much better !!woven really has had its day and should be left on the shelf !!there are much better materials that can be used , i promise you !!

 

I have already gone through three rolls of 2408 on this job. I had some mat left over and I needed another hundred feet of structural to finish up. Roving is cheap and in this case it was no real hassle. When you work for fisherman saving money where you can helps ....

 

Probably your roving does not have a "sizing" compound or it got wet and dissolved the sizing. Our purchaser bought a lot of WR from China because it was cheap. It would not wet out properly. I get dry patches. I had to throw away tons of that stuff.

 

so who you going to blame ??

The supplyer knew what he was getting and if one buys such crap then crap is what you end up with !!
Perfect example of what i been saying in a few posts recently . so who is the silly one and who you going to blame ??The chnese company ? the smart guy thats the supplyer ?? or the guy that thought he was getting the deal of a life time ??
Old story, you get what you pay for !!dont pay much !!dont get much !!

We used to use lots peel ply on a big job we were doing , i watch the transport company driver drop a brand new roll fair on its end ONTO THE GROUND so walked up to him and said put it back on you truck and take it back to your depot because you just stuff the whole roll and made it unuseable !!
I had seen this before and never could find what caused it untill that time !!
Because its slippery it gets small wrinkles over the whole surface of the whole rolland there is no way of flattening it out at all ,so one not happy driver had some explaining to do
Same happens with rolls of glass cloths !!, drop it on its end you get wrinkles and they dont come out and its a bummer of stuff to lay !! HANDLE WITH CARE !!

 

But are you really saving money ?? with a better glass that wets and dosent have dry spots will be stronger , quicker to lay and gives a better over all job, to me is a better option to use better glass !!
Do you get any thanks for using cheaper inferior product ??

 

Ouch! That sounds just like something I would say to an owner who was trying too be cheap. Did I get any thanks? I think so. Did I get paid? Just barely. It was a simple matter funds. That speech had already bled my turnip dry. When you have to turn the owner upside down to shake the change out of his pockets the show is over.

I agree 110% roving is outdated and should be left on the shelf or even out in the snow! But sometimes you just have to… ....

 

No it is the purchaser Who does not know anything! He is a dummy. He buys the cheapest available. I insist on test materials before switching brands but he got away that time impressed by the colorful brochures and internet sales talk.

It is not China per se. Some companies have good quality glass. Maybe what was sold to him are insulating glass or commercial glass, not for building boats. Or maybe just like you said, the supplier is unscrupulous.

 

When shipments of glass arrive and like you say its not the usual you are used to using then a couple of mtrs is cut off the roll and weight checked and the quality noted then the laminating test for wet out and drape and any signs of other problems !!

Interesting artical in the last proffessional Boat builder magazine Written by Richard the Honey man from Gurit on this very topic, plus glass quality and weight consistancy or inconsistancy and things pertaining to that subject !! Well worth a read !!! :idea:

 

Hahaha. Shake out the old scrooge. I like that.

No no no. Woven Roving is still as good as ever for traditional boat building. What you should watch out for is the modern materials such as Biax, Triax, Unis. It needs careful strength analysis. Strong yes, but with greater packing efficiencies, the resulting laminate is thinner. Thin laminate=more flex. Add extra layer to gain thickness=heavier laminate.

Note that roving is a collection of tows (individual strands). When the rovings are interlaced to form a fabric, it is called Woven Roving (WR).