Structural fibreglass

[Guest]

I’ve recently moved to a home which has a tidal river at the foot of the garden, with mooring rights – great, eh? So I just have to have a boat for fishing and fun, and have been offered, very cheaply, a tatty 17’ 6” x 6’ 6” fibreglass centre-cockpit cabin cruiser. It appears to be a one-piece hull and a one-piece superstructure which is pop-riveted together around the edge. What I want to do is remove all the superstructure except the foredeck and the 6” wide side decks, strengthen the hull in some way to compensate, build a small cuddy and console forward and deck the remainder as low as possible. I have no experience of this, and would appreciate any advice. Is this idea feasible? If so, what would I cut the fibreglass with – a circular saw, or maybe an angle grinder? I have practical skills, but no experience of fibreglass, and invite any advice. Thanks!

 

[eddieperkins]

John,
Definatly feasable. Set the boat up ashore and support the hull well to stop it twisting while you are working. Cut the grp with an electric jigsaw ( wear a mask and a coverall) around the superstructure leaving a couple of inches above the deck level. This will give you a stronger and more stable structure for further work. You can then fit timber around the lip and glass it in to take the superstructure and add strength. If you intend to use grp for the cuddy you will need to make a femail mould first, polish and wax it then lay up your structure. Its all reasonably straight forward but I would suggest a visit to your library or try www.cfsnet.co.uk to get a book on the subject, its too much to cover in detail here. You could also try Glassplies on 01704 540626 for an information pack and price list to give you some idea of what to do. Good luck and happy boating
Eddie

 

[jfm]

Yes feasible. But consider carefully whether it's worth the time and effort. I mean you could just buy a second hand boat that is already built the way you want, and sell what you have.

If you decide to go ahead, just follow commonsense, it is low tech stuff. Cut GRP with a jigsaw mostly, but circular saw (goggles a must) with a fine TCT blade is ok for straight runs. Angle grinder works well for trimming, will cut too, but will make a lot of horrid dust and you will itch for ages.

Working with new fibreglass is easy, the aforementioned glassplies in Southport is best and cheapest supply. They supply pretty detailed helpsheets, quite quaint as they are produced on 1960s printing equipment long before DTP invented. If you live nearby, go and buy over the counter and you will get fantastic deal, as in all material qty rounded up and all prices rounded down, speshully if the guy with the dog (doberman) is serving - take some fillet steak strips to distract it.

For the cuddy consider making a mould in melamine face chipboard and casting the whole thing in GRP.

You will find the cost of mechanics for your steering console, plus any bits you need from a chandlery, plus purchase of tools, quite high. Hence you should look carefully at buying something else before starting. Best of luck anyway

JFM

 

[Guest]

Is it really worth the effort? I'd say no. At the moment it's a cheap cabin cruiser, soon it'll be a cut about cabin cruiser and worth nothing at all. So just drive it about a bit in worry-free fenderless contentment. Otherwise it won't be finished till after the summer (which ends soon). Or compromise and drive it about till september, and go mad with the hacksaws then mebbe? Your main prob is finding a nice new name (sugg,: "actually yes I DO I own the river, sort of!").

 

[Guest]

I love all the "it's feasible" answers you have been given - and "Yes" the people are undoubtedly correct and I bow down before their knowledge and expertise.

However, before attempting to work in fibreglass yourself consider the following questions which (despite numerous attempts over 25 years) I have never successfully answered:

A) How can something so inanimate as fibreglass mat manage to get everywhere and make me itch?

B) How does the resin manage to work its way from a brush or a roller to half way up my forearms?

C) How does anyone make the resin stick to the fibreglass mat and not the roller or the brush?

D) Why does the resin set within 10 seconds of mixing - despite the fact that I measure the "Part A" and "Part B" bits to within a milligram?

I have now given up even attempting to work with the stuff.

If a bit of Araldite or Epoxy Filler won't cure it I get in a professional and stand back amazed at what they can do.

Best regards )

Ian D

 

[Guest]

John,
Please consider the following. If the hull is made of poly resin you will get a much stronger bond using an epoxy resin.
Do some estimates on what you will require and get some quotes for the materials and I’m sure you will discover the cost is way too high for what you will finish up with.
However if you insist on going ahead and don’t want to itch for days try this.
Before you start, have a very hot bath / shower and pad yourself near dry and smother yourself in talcum powder: the idea is to get it into the pours of your skin. Now put on some overalls and tape the openings around the neck, legs wrists and over any zippers. At the end of the day jump back into the bath / shower and make it hot to open the pours and allow the talk and fibreglass out. A must at all times is mask, goggles and earplugs. Good luck.

 

[Guest]

Well, fellers, you sure know how to put someone off an idea! I have visions of a dermatitis rash from head to foot for days.

I know the idea may not make sense in financial terms, but
1. The boat only cost me £150
2. It has been my dream for years to live by the water, and having been offered this boat, I want it NOW!
3. I like a challenge, and I've never done anything like this before.
So I may be insane, but I'll take sensible precautions, and cut the fibreglass when there's a wind to take the dust away from me (the boat will be dry, up on two piles of pallets and against some piles, at neap tide when it will stay dry for a week).
And I've decided I have a good enough reason to buy an electric crocodile saw (saw a nice Bosch in B & Q for only £69!)

So give me some encouragement now, and tell me what sort of glass I should use for the cuddy windows.

Regards, John

 

[Guest]

Re: oh i wouldn\'t do it like that...

Perspex is the very stuff for cheap windows. Seal it with silicon or (to avoid that total total bodegup look) use masking tape before applying any silicon. Or buy a window kit but this will almost certainly take the expenditure above the entire cost of the boat, and unfortunately it will still look depressingly crap after all the effort.

Sorry i/we are bit neg. But we are jealous/impressed that a) you having the mooring at the bottom of the garden and b) you buying a boat for slightly less than the cost of a reasonable sized fender. True boating freedom.

Much more of a challenge would be to fix up this boat spending absolutely sod all. Hmm? There's a different approach. Anything allowed, except expenditure. Much more interesting than that changing rooms crap tv program, the resulting craft easily the best value boat around, and you'll be still smiling when there's a big crashing noise outside the pub.

 

[Strathglass]

Why not ?

There are lots of reasons given by the establishment as to why you shouldnt do it. But Grp resin is relatively innexpensive especially if you buy re constituded stuf from Glassplies. Mix it in calibrated 500ml containers and use a syringe to add the catylist. This way you can control and get consistancy of setting time. If the contents of the container starts to set when using it through it out the boat and use less hardner the next time. Before removing the deck brace the hull securely and after removing it fit two temporary deck beams across the hull to hold it together while working inside.
There is no reason why wou should be able to complete a clean and tidy job at a cost effective price. The main cost is labour and ALWAYS wear protective clothing particularry when grinding and laminating. Add at least 50% to both your cost and tims estimates. Best of luck Iain

 

[jfm]

Re: polyester resin

The reconstituted resin is pretty horrid, it's got runny bits then gooey bits, kind of like snot. I'm not convinced it's worth the £ saving.

Strictly when mixing catalyst to resin you should not vary the ratio to control the curing time. Many people use less catayst in hot weather, to give them more time to work, but really if you're being pukka you should use a constant mix and just mix less qty in hot weather. Otherwise the wrong mix will screw up the long term (3months) cure that takes place, and the hull is weaker. I agree it matters not much if you're making a garden pond but no boat manufacturer would muck about wiv the ratios when making a hull

JFM

 

[Guest]

Re: Hacking the glass about

OK, I've bought the electric saw, so the boat definitely gets the chop! Bought a pack of blades for everything, but no mention of fibreglass. Do I use blades for wood, or for metal? Advice please?
P.S. also bought an expensive filter mask which should keep out the nasty bits!

 

[Guest]

Re: Hacking the glass about

John

Wood/aluminium ones seem to be best but "burn out" really quick if used at high speed.

Own experience is to use "ripper" type (i.e. wood/aluminium) but at a very slow speed so that they don't get hot.

I use a Bosch jig-saw and find fast = quickly knackered blade regardless of type.

Also - despite filter mask I find it is useful to have a vacuum running with the nozzle alongside the saw. This stops having to clean up the mess afterwards!!

As an added tip (see previous message) I actually used fibreglass successfully for the first time today. It was a "pre-mixed" can of chopped fibreglass already mixed with a resin and just waiting for the hardener to be added. (Compliments of a local car repair shop.)

It still went half way up my hands - but at least it seems to have done the job.

Best regards )

Ian D