Resin for keel.

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doug748

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I need to pour about 2 ltrs of resin into my encapsulated keel to fill a void in the bilge. This is not a repair but just to prevent bilge water getting in and festering. Strength is unimportant.
I would guess that all polyesters would be too gloopy and envisage using epoxy. The more runny the better. I am pretty sure I will be pouring it in one shot.
The questions are:
Has anyone done a similar thing?
Can you reccommend a suitable, very runny, resin?
Bet it got 'ot - did you reduce the amount of hardener?
 
Epoxy resin gets very hot when mixed in large quantities and left to go off . You really need to talk to one of the manufactures / suppliers for the best product to use. Epoxy will happily melt a plastic cup. :eek: Just reducing the hardener does not necessarily mean it will not get hot. It might never harden
 
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When my keels were ballasted with steel stampings after each 60lb bag of ballast was poured in ( 6 bags in each keel) 1lb of catalysed (polyester) resin was poured over it and stirred
That was sufficient resin to thoroughly coat the stampings but not to completely fill all the voids.

When set the spaces left above the ballast were filled with a two part polyurethane foam mixture. The tops were covered with waxed ply boards held down ( stood on!) to restrict the foam expansion.

When set the top of the foam was sanded off flush with the inside of the hull and then glassed over with several layers of glass mat.

( That's all according to the building instruction book)
 
doug748 said:
I need to pour about 2 ltrs of resin into my encapsulated keel to fill a void in the bilge. This is not a repair but just to prevent bilge water getting in and festering. Strength is unimportant.
I would guess that all polyesters would be too gloopy and envisage using epoxy. The more runny the better. I am pretty sure I will be pouring it in one shot.
The questions are:
Has anyone done a similar thing?
Can you reccommend a suitable, very runny, resin?
Bet it got 'ot - did you reduce the amount of hardener?
Click to expand...

Could you fill with foam then glass over with resin and cloth?
A 2 litre lump will get extremely hot.
Clyde Wanderer will be a long shortly to give his expertise, he's done loads of fibre glass work and now works in the industry
 
Spyro said:
Could you fill with foam then glass over with resin and cloth?
Click to expand...

No afraid not, the space is below a GRP floor and only a narrow gap is visible.

I have done a bit of research and see that SP do a resin with "slow" hardener and that may be the way to go. I always like to hear what others may have done though - before I consult the salesmen.
 
doug748 said:
I need to pour about 2 ltrs of resin into my encapsulated keel to fill a void in the bilge. This is not a repair but just to prevent bilge water getting in and festering. Strength is unimportant.
I would guess that all polyesters would be too gloopy and envisage using epoxy. The more runny the better. I am pretty sure I will be pouring it in one shot.
QUOTE]

First of all do not do this until you have a defintive answer from the resin supplier/manufacturer.

I am pretty sure they will tell you to do it stages so the max thickness of any one layer is less than 10 mm.

I have seen a half litre of polyester resin catch fire in a cup.

You MIGHT be OK with a very slow hardner but even then I suspect that this might overheat if the resin collected in a thick lump rather than a thin layer.
Click to expand...
 
I would not use 2kg of resin, instead I would buy 1kg and add an inert filler, probably mix about half or less at first and mix in an equal volume of the filler before adding the catalyst. As for a filler there are things sold for the purpose, but for your use dry sand would be my suggestion.
 
Epoxy resin can be thinned by adding up to 30% Methylated Spirits to the mix.

Adding any fillers will only thicken the mix and reduce it's ability to flow into small areas and crevices.

It can 45 minutes for a mix to heat up so small amounts with at least a few hours between applications will help.

It will take 24 hours with temperatures around 20C to fully cure.

Good luck.:)
 
Adding filler will not mean the epoxy wont heat up. I've had smoking filler before (epoxy/microfibres/colloidal/bubble) that just seemed to expand. Reducing the amount of hardener will just mean it won't set properly. You need surface area so the heat can escape...for example epoxy mixed in a roller tray will stay liquid much longer than the same volume in a cup.

Have you thought about this stuff, with a thin layer of epoxy over the top to seal the water out?

http://www.ecfibreglasssupplies.co.uk/p-1717-polyurethane-foam.aspx
 
did you reduce the amount of hardener?
Click to expand...
You must mix an epoxy resin and its hardener accurately in the correct proportions because the two react together. Insufficient hardener will mean it wont set properly.
Different hardeners may be available for different setting rates

You can reduce the proportion of hardener mixed with a polyester resin to control the rate at which it sets because it is only a catalyst.
 
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ripvan1 said:
Is bitumen (heated and poured) an option, I see it's not for strengthening ?
Click to expand...

+1

We use hot pitch to fill voids usually around stem planking and king planks on wooden boats and it works extremely well.

The big plus side is that you can remove it without too much bother if required, which you will have mega difficulty doing if you use epoxy or polyester.

Very much cheaper too.
 
Resin

I would use polyester resin because it is possible to vary the amount of hardener to vary hardening time and it is cheaper. You might want to experiment with hardening time in a cup with various percentages of hardener. (and ambient temp.) Use the min amount of hardener that will harden a cup full in 24hrs. Even then do it in stages. ie leave several hours between layers.
If you want to use epoxy as said add methylated spirits to thin it and then do it in stages. good luck olewill
 
alahol2 said:
Would sloppy concrete be any good?
Click to expand...

That's the way to do it. It's also cheaper and denser.
Seal over the top with resin if you want belt and braces, but probably not really necessary.

As an aside, I fairly sure that glass beads are not recommended below the waterline.
 
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I've seen someone frantically spraying the outside of the keel with a hose after pouring resin. Although in your case access may be a problem I would fill with sand and cover with thin ply or nedaplas and 2 x 600 gm mat/resin. Cement is easy if you never want to remove it.
 
doug748 said:
I need to pour about 2 ltrs of resin into my encapsulated keel to fill a void in the bilge. This is not a repair but just to prevent bilge water getting in and festering. Strength is unimportant.
I would guess that all polyesters would be too gloopy and envisage using epoxy. The more runny the better. I am pretty sure I will be pouring it in one shot.
The questions are:
Has anyone done a similar thing?
Can you reccommend a suitable, very runny, resin?
Bet it got 'ot - did you reduce the amount of hardener?
Click to expand...

Talk to a resin manufacturer or quality supplier. There are slow setting polyester resins made for the job, to reduce the exothermic reaction (heat). Just reducing the catalyst will not do - you will either get too much heat or a mix that does not set properly, depending on just how much you cut back the catalyst.

Resins are actually three parts, resin, catalyst and accelerator. Small retailers rarely sell accelerator separately as it can cause an explosion if mixed directly with catalyst, so most general purpose resins are supplied pre-mixed with accelerator.
 
The keel will be an enormous heat sink. I doubt there would be a problem particularly as the voiud is probably laminar.
 
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