Epoxy Filler

Fire99

Fire99

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Hi people,

I'm starting on the cockpit floor rebuild now and would appreciate some advice.
I've decided to fibreglass over the original plywood, which has now been sealed with SP Epoxy Sealer.
The plan is to add woven fibreglass over the ply using SP106.

The question I have is that the ply surface is a bit uneven (due to surface damage) so my plan is to fill the surface with epoxy filler before adding the woven fibreglass, what should I use to fill the surface?

I've seen microfibres, microballoons, Colloidial Silica which you can add to the 106 but it's a bit of an unknown science to me.

What do you recommend to create a flat surface on the ply, to add the fibreglass?

many thanks,

Nik
 
Fire99 said:
Hi people,

I'm starting on the cockpit floor rebuild now and would appreciate some advice.
I've decided to fibreglass over the original plywood, which has now been sealed with SP Epoxy Sealer.
The plan is to add woven fibreglass over the ply using SP106.

The question I have is that the ply surface is a bit uneven (due to surface damage) so my plan is to fill the surface with epoxy filler before adding the woven fibreglass, what should I use to fill the surface?

I've seen microfibres, microballoons, Colloidial Silica which you can add to the 106 but it's a bit of an unknown science to me.

What do you recommend to create a flat surface on the ply, to add the fibreglass?

many thanks,

Nik
Click to expand...

You need something that's easy to sand so I would suggest microballoons.

Have you got the data sheets etc that you can download for SP products (and WEST epoxy)? They are very helpful
 
parsifal said:
You need something that's easy to sand so I would suggest microballoons.

Have you got the data sheets etc that you can download for SP products (and WEST epoxy)? They are very helpful
Click to expand...

Thanks for that.. I'll grab the datasheets and have a nose at them. Some of the online info is a bit over-technical about the specifics of the additives.

It's not a 'finished' layer so I don't want it to be rock hard and smooth, just make the surface flat, ready for the fibreglass.
 
Fire99 said:
Thanks for that.. I'll grab the datasheets and have a nose at them. Some of the online info is a bit over-technical about the specifics of the additives.

It's not a 'finished' layer so I don't want it to be rock hard and smooth, just make the surface flat, ready for the fibreglass.
Click to expand...

Have a look at the WEST epoxy instruction books. They are more user friendly, and well-illustrated.

eg http://www.westsystem.com/ss/product-selection-chart/
 
TQA said:
I am assuming that you intend to sand this layer.

Do be aware that epoxy dust is nasty stuff and it often has a cumulative effect leading to a serious allergy issue.

Ask me how I know this.
Click to expand...

Yeah it will be sanded enough to be flat. I'll make sure I use dust masks etc. Thanks.
 
Microballoons is the most appropriate for non structural filler as it is easy to get a good finish and relatively easy to sand if you go over. Wood fibres can be useful to bulk up the mixture cheaply, but don't give such a good finish as it does not spread so well. Would be fine if you are just levelling before sheathing. If you are going to be doing a lot of epoxy work, worth buying a tub of each and experimenting with different mixes. Silica has its uses to thicken epoxy when you are using it for structural bonding, but it is really tough to sand.
 
You are using the word 'fibreglass' but of course what you really mean is woven cloth suitable for epoxy, not fibreglass.
Balloons or filleting compound will be fine, colloidal silica is really what you would use to take big compression loads such as the coring underneath the mast foot..
Many sanders, even the cheapest from the sheds, can now be hooked up directly to a vacuum cleaner whilst running..
Plywood wants to be at 15 degree c or more really for doing the work, you can always stick a fan heater under the cockpit floor and a cockpit cover at night to keep condensation off. enjoy, fixing your boat better than new can actually be fun and rewarding. It aint rocket science,,''fools build boats that rich men buy, an old saying"...
 
Thanks guys for the replies. Yeah I use the term Fibreglass a bit liberally. I'm actually using woven cloth (not stolen from trousers either. :) )
I've some microballoons on order and i'll have a bit of an experiment.

I'm quite looking forward to completing my first major job since acquiring the little boat. The cockpit was always a bit sorry looking so hopefully if I take my time, she should look much nicer afterwards and more watertight too..

Well that's the idea anyway. :)
 
The cloth needs to be epoxy compatible - not GRP resin compatible. Take care.
It will add some weight, but it is low down.
Do scrape to as flat a finish as possible - much easier than sanding.
ken
 
kds said:
The cloth needs to be epoxy compatible - not GRP resin compatible. Take care.
It will add some weight, but it is low down.
Do scrape to as flat a finish as possible - much easier than sanding.
ken
Click to expand...

Many thanks for that.. On the bright side, whatever I do will be lighter than what was there before. It had more bodged layers than a wood/fibreglass trifle..
 
It will be interesting to hear how you get on and exactly what materials you use.

I have small "repair" job to do.
I'd do it with chopped strand mat and polyester resin without a second thought as I've used plenty of that in the past. However I want to do this job with epoxy for a couple of reasons but I've not used epoxy before.
I see something called "biaxial" cloth. I suppose that what I will use but unsure about the different weights offered
 
VicS said:
It will be interesting to hear how you get on and exactly what materials you use.

I have small "repair" job to do.
I'd do it with chopped strand mat and polyester resin without a second thought as I've used plenty of that in the past. However I want to do this job with epoxy for a couple of reasons but I've not used epoxy before.
I see something called "biaxial" cloth. I suppose that what I will use but unsure about the different weights offered
Click to expand...

Well to be honest, I'm currently 'winging it' using info from you guys on here, and a bit of reading up on West Systems docs etc.
I'll certainly keep the thread updated with my results. My only grumble so far is that Epoxy Resin seems blinking expensive when purchased in any quantity.

We shall see. :)
 
ripvan1 said:
Cheaper to re ply the floor ;)
Click to expand...

So true!! But "I've started so i'll finish" and i'll get some good 'glassing' experience and playing with epoxy. Not to mention my boat will be more epoxy than GRP by the time i've finished so I doubt she'll rot. :D
 
Just replaced the transom on a boat of mine using a mixture of west systems epoxy and polyester resign fibreglass.

The colloidal silica is quite nice to work with. I got a big tub of it and 6 litres of epoxy resin etc, along with a few meters of woven roving etc etc. All worked really well. Just need to finish it off cosmetically now :)
 
VicS said:
It will be interesting to hear how you get on and exactly what materials you use.

I have small "repair" job to do.
I'd do it with chopped strand mat and polyester resin without a second thought as I've used plenty of that in the past. However I want to do this job with epoxy for a couple of reasons but I've not used epoxy before.
I see something called "biaxial" cloth. I suppose that what I will use but unsure about the different weights offered
Click to expand...
You can get small quantities of cloth from Blue Gee (and no doubt other GRP suppliers) in various weights as either cloth or tape. Pretty sure the one I use most commonly (actually I only have the one piece!) is 200gsm. I have a 1m square piece that I cut pieces off to shape as I need them. Very easy to work - lays well and wets out thoroughly.
 
Fibre glass

For the OP Microballoons would be the preference for filler. You must of course paint the epoxy to exclude UV which will damage the epoxy over time.

Vic AFAIK biaxial means equal strength in both directions (warp and weft) for the cloth. ie that is just ordinary cloth. AFAIK woven cloth is OK for both polyester and epoxy resin (and any other resin) being pure glass with no filler. You will find the epoxy more difficult to work make sure you get correct ratios of resin and hardener (typically 1:1 , 1:2 check the instructions). needs warmth for hardening but much better final job especially on wood. But needs painting. good luck olewill
 
Anybody seen the Mark Evan's series on building your own aircraft, "A plane is born" bit anal on epoxy, but explains different cloths and demonstrates using epoxy. Bit of a drift, but is useful for people who have not worked epoxy before.
 
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