Fibreglass

In message , Himszy writes

[snip]

As they used to say on the 'Goon Show' (a radio programme from long before your time) - "A young lad could come to harm that way".

For the benefit of your own health and in the interests of family harmony. Do it outside in the open air!

Good luck anyway!!

Neither. It's GRP. Glass reinforced plastic. Glass is the fibre reinforcement, the matrix it is embedded in is the plastic, usually polystyrene which is formed from the styrene resin. The odour will go once the resin has fully cured.

Cliff Coggin.

1. fiberglass is made from glassfiber and resin.

1. How strong does it need to be ?

Hull diameter, size and shape of hatches, and operating depth will be the important factors in determining strength, then it's a case of what type of matt, ( chopped fibre, woven, directional ) and what weight.

Design of pressure vessels to resist external pressure is very different to the design of vessels to hold internal pressure.

1. work in clothes of natural material, nylon attracts fibre and you will itch... Do not wash your work clothes in the same load as your wife's underwear.... :-)

The fresh moulding will smell for at least a week, and a sensitive nose will probably detect a smell for a month.

I lost my ability to smell acetone when I went on a laminating course.. I still have not really got my sense of smell for fibreglass fumes back.

I'm pretty sure that Fibreglass is a registered trademark.

Number of layers - depends on the thickness of the glass mat and whether it's woven or chopped strand and what you want the finished item to withstand.

Will the smell ever go? Some smell will be there for ever inside the finished hull. The smell of the resin will eventually go in the place where you laid up the hull - of course you have ensured that this is well ventilated and at a suitable temperature to ensure the resin cures.

Many years ago I built a Mirror dinghy. Plywood with resin bonded glass tape to make the joints. I started in the garage but it proved to too cold to cure the resin properly (it was winter) so I moved into the dining room. The smell did go quite quickly and didn't seem to affect the wife or children - and we are still married after 41 years:o))

\Himszy wrote:

How will you get the radio waves to it when it's under water? Or is it a submerge once submarine?

I believe the mixture of glass fibre and resin is more generically known as GRP (Glass-fibre reinforced polyester).

Regards, Tony

Malcolm Stewart writes .........

I believe that this technology now exists. Have seen submarines in action at the ME as far back as Olympia.

Google on Radio Controlled Submarines - there are quite a few small, cheap offering available

Mike

GRP is VERY strong. I'm not sure how big the s/m is, but for normal size models, you probably won't need a very thick hull - as long as you won't be going more than 10' or so down.

You probably don't need standard matting - try tissue, a much finer version. Do a trial by coating a piece of flat plastic with release agent, 'Kantstik' is very good, then apply a coat of gelcoat. The gelcoat can be coloured beforehand, or you can get coloured gelcoat. When the gelcoat is set, paste a couple of layers of tissue over it with laying-up resin. Allow to set, then try it for strength - you'll be surprised!

You need plenty of ventilation for this work, but the work (and setting) needs to be carried out at at least 15 deC, preferably 20 deC. Get plenty of disposable gloves, have some acetone handy (cellulose thinners works, too, but not as well) for cleaning up. Wear old clothes or a disposable plastic apron!

Enjoy.

Enyoy

As well as glass-reinforced plastic (GRP) where the plastic is most often polyester there is GRE where the binder is epoxy.

Stephen

Raise the temperature while it cures. With the epoxy I use I cure it at about 70-80degC for about 4 hours and there is virtually no residual smell afterwards.

Also you can get 'safe' epoxies that have a much lower volatile content, and hence less smell and less risk of epoxy sensitivity.

Stephen.

...and, of course, GRC, which is glass reinforced concrete. Probably more suitable for building larger boats though ;-)

Regards, Tony

I have done it outside but after around 3 weeks the smell is still very strong.

Michael

Perhaps I should get my 6' 'S Class' sub finished. What are you building? I would be interested in you ballast system plans.

Its my own design based on a nuclear sub. In total it will have 8 ballast tanks, which will be grouped into 2 sets. What about your system?

Do you know of any clubs around the B'ham area?

It was some years ago I started it. It had a twin piston pump inflating air bags. I had real difficulty with that system, if it went down level then it would not come up level or visa a versa. I would love to see the detail of your system.

I am a reasonably proficient at amateur grp yacht construction and maintenance. In my experience most retail outlets such as chandlers and motor factors have grp materials that is almost useless for any serious work and I found it far preferable to buy fresh materials direct by mail order from a manufacturer or from local grp moulder. You can save a lot of money by buying reprocessed resin (this is just resin that has been strained and reaccelerated) and seconds mat (nothing wrong with this either but it is the start and finish of production runs where the edge selevage is a bit tatty which doesnt matter to most amateur constructors.) Also some of these comapaies have quite helpful info free sheets. Googling produced an example,

(I have no connection with them and haven't used them )

I have used them - I especially asked them to pack some carbon fibre cloth rolled and padded so it wouldn't crease or pull apart, and they did that well for me, so a plus point there. On the other hand, people who sell carbon fibre cloth should routinely pack it that way - but they often don't.

Unfortunately, most of the rest of the order was slightly damaged - leaking packets etc. - so it wasn't all good. I didn't ask for a replacement, it wasn't that much lost, more annoying than anything, but they did offer to "add a bit more to my next order" to make up for that though.

The other thing is that the quality of most of the stuff I got from them would be best described as "cheap". It was fairly inexpensive, so fair enough, and it all works, but it's not top notch.

I would not recommend using reprocessed resin for a model, the saving just isn't going to be worth it. Reprocessed resin has used up some of it's most gung-ho "stick-to-itself-ness", and it can never be as strong as fresh resin. Nor can it ever be as easy to use, and it will not have such a reliable pot life.

Not would I recommend the use of "low cost" resin, which is reprocessed resin mixed with fresh resin. Sure, if you are building something big and ratty they can save you some cash, but for building small scale stuff I'd stick with the quality.

And as Chris said, most importantly: don't buy locally, especially resin, it goes off. Get it fresh by mail order. You won't just notice the difference, you will be amazed at it, and think you are working with something entirely different.

Store resin in a cool place until you want to use it. Only use it when it's warm. If you don't do both of these resin can take ages to set - sometimes it will never set at all, or will remain tacky - it will be weaker, and it will smell for longer. Some resins will thicken to uselessness if stored warm.

It's a good idea to cure a made piece at about 80 degrees centigrade for a few hours after it sets, it makes it much stronger and stops any smell. I use a hairdryer and make boxes of cardboard and for larger pieces foam polystyrene insulation covered in polythene film stuck together with masking tape (so I can reuse the cardboard, foam and film) to keep the heat in.

If you are building a submarine that isn't huge, you could be much better off using epoxy than polyester. It is much stronger, less brittle, doesn't smell much, and while it used to cost an arm and a leg compared with polyester, it's only half an arm more now. It's a little trickier to use, beware of fisheyes and combusting pots - read the instructions - but not that hard.

Actually epoxy resin is now about four times the price of polyester resin, but an epoxy/glass composite can easily be four times as strong as a similar polyester/glass composite, so it pretty much balances out.

Someone suggested using glass surface tissue rather than CS mat or cloth. I like cloth myself, but tissue is good too. I use tissue quite a lot on light to medium models because light weight cloth is expensive, even more expensive than heavier weight cloth is, go figure - but submarines don't have the weight considerations flying models have. Tissue also gives a much better finish than CS mat.

The cost of carbon fibre would not be justified for a sub, because again there aren't any weight considerations. If you can get some kevlar socking at a reasonable price though it might be worth adding a layer of that to the glass, as kevlar/glass/epoxy is much tougher and less brittle than straight glass/epoxy (which is much tougher and less brittle than glass/polyester). But reasonably priced kevlar is - difficult - to find :(

A quick tip for making epoxy tanks and similar hollow shapes - cut a block of foam polystyrene to the right shape and size, and cover it with glass and resin. Let it set hard, or heat cure if possible. Drip cellulose thinners through any convenient filler hole, shake for a few minutes, then rinse a couple of times with acetone.

The polysytyrene foam will dissolve away leaving the empty tank. Note that you need both thinners and acetone, and you will want to try dissolving a scrap of the actual foam polystyrene you are using first, in order to get some idea of the quantities to use, foam varies a lot. Fun to watch.

I have only done this with epoxy, I think the styrene in polyester resin might dissolve the polystyrene foam, but I have not tried it.

sell glass fibre tissue and West Systems epoxy, both of which I can recommend. The quality of their range is generally good, if you can afford the somewhat higher prices. Service seems as you would want, speedy delivery and well packed, I have no complaints, though I've only bought from them a few times. No connection, I'm just a customer.

"cool", not "cold" - ie not in a fridge, or a shed where it will freeze.

10 C is optimum for storage, 20-25 C for use.

16kHz and a long-line aerial..... No that won't work, they've decommissioned the transmitter at Rugby :-)

Mark Rand RTFM