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[Paragon]

Hi , can anyone please tell me the finest grade on fibre glass cloth you can get ?
I’m wanting to cover a wooden hull I’m making using cloth and Z epoxy finish .


Thanks


John

[SailorGreg]

Well, Easy Composites http://www.easycomposites.co.uk/#!/fabric-and-reinforcement/glass-fibre-reinforcement/woven-glass-fabric do a 25 gsm cloth which is about as fine as you could want. I use 100 gsm which is fine for a wooden boat hull, so take your pick. I have never used the 25 gsm but suspect it needs careful handling to avoid getting it in a mess.


Greg

[inertia]

I'd agree. I've used 25gsm and it's a pig to handle, especially if you have any small specks of resin or glue still on your hands. They can - and will - grab at the weave of the cloth and open it up, and that's practically impossible to fix. This will also happen if you attempt to pull the cloth in any one direction, as opposed to lifting it carefully and re-positioning it. My most recent hull uses 54gsm cloth (Deluxe Materials) and that was a revelation. It is much easier to handle, takes up the resin just as well and produces a fine surface with less effort. BTW I also use Z-Poxy Finishing Resin with 10% isopropyl alcohol as thinners.
Hope this helps.
DM

[jarvo]

Hi Paragon, i totally agree with SailorGreg, easycomposites are a great company to deal with, their website is very helpful, and they do mail order, also with Inertia i agree the 25g cloth is very difficult to work with, i use the 75g cloth without problem, not used Z-poxy i use easycompsite epoxy with AT30 catalyst,  look at Deluxe site as well they also have how to video's


Mark

[Subculture]

The finest I've used is 18g/m, available from hobbyking. That is extremely thin, but you can get lighter. I use it primarily on aeroplanes, but I did use it on a small fast electric boat in replacement of a dope and tissue finish which had seen better days.

[Paragon]

Hi all thank you for the replies. I’ll have a look and see what on that site , I might go for something slightly heavier if the light stuff is a nightmare to use .
All my hulls have been of wooden planked boats until now , this ones a steel trawler so I don’t want the plank lines to show through.


Thanks


John

[Subculture]

I've not found it difficult to use. I work with it in the following way-

Mix up a small amount of epoxy resin, you can thin this a little if you choose, and apply a thin coat of epoxy to the hull, this seals the wood. Allow to dry for a few hours until tack free.
Cut cloth to size, place to one side.
Mix up your epoxy resin, and brush a coat on the hull, working from the middle of the hull out, drape the cloth over the hull, and gently consolidate with a brush, adding epoxy where needed to ensure there are no dry spots. Ensure the hull is placed in a warm room or hot box to dry for at least 24 hours.

[Paragon]

Thanks Subculture.
I have ordered 1oz 28 gram cloth  , let’s hope I’ll be able to use it .
I’ll probably have a practice before applying to the hull . I’ll need to do it in two parts , hull then upper deck . I take it any join lines can be sanded down and fill so they aren’t seen ?


John

[Subculture]

At this thickness the cloth is so thin, joins barely show. The main thing you have to be careful of is sanding through the cloth, so don't go balmy with the wet and dry! I tend to give the hull a second coat of epoxy resin to fill any weave, then use standard polyester filler to fill in any obvious areas of the hull which may be cosmetically poor, then apply two or three coats of filler primer. Cut that back and you should have a lovely finish, and the boat should be tough and waterproof.

[Paragon]

Thanks Subculture!
I’m still planking so this is ahead of me a bit but I like to get prepared in advance.
I’ll do as you say and hopefully all will work out well .


Thanks again.


John

[Neil]

The finest that you can buy as probably other members have said but called it a different name, I use is called "surface" or "finishing" tissue............like gossamer and so light but excellent for binding and finishing.


this is what you are looking for. it's thinner than 80 gram paper by about 50%

[Paragon]

Thanks Neil I appreciate that . At least now I have an idea of what I need to buy in the future.
Looks thin enough all the same .


Thanks


John

[SailorGreg]

I am sure Neil gets excellent results with the tissue but as you are using epoxy I would proceed with caution. Non-woven glass material like tissue and mat are held together with a binder. This binder is dissolved when polyester resin is added, allowing the material to conform to curved surfaces. Epoxy doesn't dissolve the binder which makes it tricky to get the material to stick to anything other than a flat surface. Unless you are building a Springer, you probably don't have a flat surface. (You can get tissue and mat for use with epoxy but you need to ask a specialist supplier.)


Others put a coat of resin on the hull and lay the cloth onto that. I prefer to lay the cloth on the dry hull and smooth it out as much as I can with my hands. Once the wrinkles have been removed I pour some resin into the middle of the cloth and use a roller to spread it and wet out the cloth. There's more than one way to skin a cat - or boat!    It's always worth having a bit of a practice before committing resin and cloth to your lovely new hull.


Have fun.


Greg

[Subculture]

Surfacing tissue doesn't have anywhere near the strength of cloth. It's primarily for helping a polyester laminate conform with a gelcoat and/or smoothing out the inside of the laminates where it's cosmetically important.

It also tends to wick up more resin than cloth, which will result in a composite that is both weaker and stronger than one with cloth.

There are a few things to bear in mind when working with different types of composites, which are covered in various guides, and worth reading. When working in epoxy I use various weights of cloth, when working with polyester I use tissue and chopped matt (100-300g/m2).

[RST]

I have just washed my hands having done another hull in 24g/sqm cloth  from Deluxe,  and ZPoxy from zap.  I find the 24gm/sqm cloth quite easy to use -but you need a sharp pair of scissors to cut it without it pulling.  The ZPoxy resin I found last year, previously I used Davids Isopon polyester resin  from auto factors*.  I fund it critical on the mix and use a small coin? scales for mixing 10-15g of each part before thoroughly mixing.  I used to use a cheap artists brush but just used a 3/4" "sponge" decoratoes brush and found it much better (almost perfect).  I guess practice makes perfect, it's about the 3rd hull I've done from the same cloth pack and I seem to get better at it.

I have done other cloth lay-ups before and I have never had the need to spray a fixative before.  Moreso I would not so as not to introduce a contaminate in the layers.  Having said -what works for one doesn't work for others so whatever works for you!

*and there's nothing wrong with that -it just smells allot more with VOC's!!!!  I can ZPoxy on my living room table and some natural ventillation. 

Also, I use balsa which is pretty soft.  I've taken to using rough tissue sheet first with water soluble Deluxe EzeDope.  I just did this hull with 2 coats of tissue first which let me sand back between the different woods first and get a good smooth finish and I'm quite surprised how tough it has set -but on a balsa hull I'd still advocate the GRP skin also as it's not much extra hassle or cost these days.

Rich.

[Cadser]

Is it possible to pull the cloth in all directions to get it to lay flat? I want to cover a yacht hull to strengthen it up. As the cloth becomes lighter does it become stronger in the ‘weave’ ?


Bri

[JimG]

I have found with the lightest cloth it is easy to open the weave by pulling in ome directions,this tends to leave holes. Lightweight cloth will conform top the shape of the hull if placed on carefully and shouldn't need much adjusting. Ifr necessary don't try to cover the whole hull with one piece but use smaller pieces that fit better.
Jim

[Circlip]

With the hull upside down, lay the cloth with the weave diagonal to the hull centre line.


 Regards  Ian.

[Cadser]

That’s a great idea.  I would have put it straight. 


Thank you

[GG]

Ian's description of how to lay the cloth weave is the "Bias Cut" method invented by the Parisian dressmaker, Mile Vionnnet, in 1922.  A clever way to make a dress that clings to the body shape.


Glynn Guest

[Cadser]

In the end I cut the cloth in two halves.  I ended up with a few places to smooth down that were being stubborn after it’s all hardened up.  I must say it’s not easy but the results are good.  I’m surprised how much it stiffens the balsa hull.


Bri