Best filler/mixer to use with epoxy (ferro hull)

[Kumuka]

Hello all,

Wondering which of the West System products will be best to use for small repairs to a ferrocement hull with their 105/205 epoxy:

403 microfibres
406 colloidal silica
407 low density filler

Any advice gratefully received...

Thanks,
Steve.

[Lepke]

No ferrocement experience...
I'm a former shipwright and done lots of commercial wood boat construction and repair. West is my favorite and never buy anything else. I use 404 high density almost exclusively. Sometimes I use micro fibers when I am spanning a small thin area too small for cloth or rsm. The 404 HD has additional adhesive properties and takes severe abuse. When deconstructing the wood fibers split before the bond breaks. I also use it for renovating screw holes and usually always epoxy in new screws. In time water always finds a path along side a screw and epoxy holds wood better than a screw.

[HankOnthewater]

Have experience with repair and maintenance of four ferro boats (one of them my own). Used West system only once as that what the owner had. I generally used plain budget priced epoxy (thickened) that mixed in a ratio 1:1, the brand I used most is BoatCote.
If I needed to use chopped, woven mat or dynel sheet, used less viscous epoxy that normally mixes with a ratio 1:4 or 1:5. I only mixed that with microballoons or Q-cells if I needed a surface that is easily to sand. Weight savings on a ferro boat was not a consideration. Also last few years did not bother with mixing microballoons anymore and used Wattyl EFC like this http://www.wattylindustrial.com.au/d...robrochure.pdf

I must say never used polyester resins on a ferro boat, except for some hasty repairs on the deck of my newly (then) purchased boat. Used cheap car filler 'bog' with the view to do a proper repair later on. Ten years later, when doing a complete deck repair, that cheap bog was still in place, no cracking, with good adhesion, so I never dug that out, and still in place after 20 years. would not use that cheap filler under the waterline though.

Bottom line, in my opinion there is not much benefit to use high price/premium epoxy products on a ferro boat, and certainly not above the waterline.
If you need more specific information, just ask.

[Kumuka]

Thanks for the replies, I've been looking at the product sheets and I think I'll go with 407 as it will need to be sanded. Interesting that the car product lasted so well though, I do wonder whether it's worth paying a premium for West System but as it's got such a good reputation and it's not megabucks for relatively small quantities I think I'll go with that...

[HappyMdRSailor]

Originally Posted by Kumuka

Thanks for the replies, I've been looking at the product sheets and I think I'll go with 407 as it will need to be sanded. Interesting that the car product lasted so well though, I do wonder whether it's worth paying a premium for West System but as it's got such a good reputation and it's not megabucks for relatively small quantities I think I'll go with that...

In your first post, you didn't mention what "repairs" you were talking about...

For fairing, definitely stay with the easily sanded families... West filler is WAY overpriced in my opinion... (well... and their resin too, but less so)

Try Fillers

[Scaramanga F25]

Talk to the WEST people. They really know and are very approachable.

[Cadence]

Originally Posted by HankOnthewater

Have experience with repair and maintenance of four ferro boats (one of them my own). Used West system only once as that what the owner had. I generally used plain budget priced epoxy (thickened) that mixed in a ratio 1:1, the brand I used most is BoatCote.
If I needed to use chopped, woven mat or dynel sheet, used less viscous epoxy that normally mixes with a ratio 1:4 or 1:5. I only mixed that with microballoons or Q-cells if I needed a surface that is easily to sand. Weight savings on a ferro boat was not a consideration. Also last few years did not bother with mixing microballoons anymore and used Wattyl EFC like this http://www.wattylindustrial.com.au/d...robrochure.pdf

I must say never used polyester resins on a ferro boat, except for some hasty repairs on the deck of my newly (then) purchased boat. Used cheap car filler 'bog' with the view to do a proper repair later on. Ten years later, when doing a complete deck repair, that cheap bog was still in place, no cracking, with good adhesion, so I never dug that out, and still in place after 20 years. would not use that cheap filler under the waterline though.

Bottom line, in my opinion there is not much benefit to use high price/premium epoxy products on a ferro boat, and certainly not above the waterline.
If you need more specific information, just ask.

I think the cheap auto bog is what we call Bondo. I was going to suggest that.
I'm sure that won't sit well with some. Cheap and if it sticks to auto bodies it will stick to Ferro.

[minaret]

Be sure to acid etch bare cement before applying anything.


Using Muriatic Acid To Prep Cement Floor For Epoxy | Grants Painting


Then if you have much fill use 403 with 407 over the top. Or use 3M vinylester High Strength putty.

[s/v Jedi]

The negative of the 407 is that it is plastic based and the sun can overheat it. I prefer microballons where it gets hot.

[cruisersfarm]

Would like to know the actual application here.

Specifically, what repairs are we making?

Filling in scratches?

Patching holes?

Reattaching a rudder?

Each case demands different fillers.

[s/v Jedi]

Originally Posted by s/v Jedi

The negative of the 407 is that it is plastic based and the sun can overheat it. I prefer microballons where it gets hot.

Oops, 407 is microballoons... it is the 410 microlight to avoid.

We assume this is for filling some gauges etc. in the concrete.

[four winds]

The Ferro part throws me....

But there is a polyester filler by Evercoat that I've used on fibreglass that worked very well over the long term. Mostly cosmetic with some load on one side but didn't want to glass it. Had my doubts but years later no problems. Stronger bond than I expected.

[minaret]

Originally Posted by s/v Jedi

Oops, 407 is microballoons... it is the 410 microlight to avoid.

We assume this is for filling some gauges etc. in the concrete.

Cement and concrete are not at all the same thing. Never heard of a concrete boat.

[s/v Jedi]

Originally Posted by minaret

Cement and concrete are not at all the same thing. Never heard of a concrete boat.

Well I believe they add sand to the portland cement which is a thin aggregate I agree so let's call it a cement plaster then if that sounds better

The thing is that I meant superficial damage instead of cracks through and through or damage to the wire reinforcement etc.

[Rustic Charm]

You havn't asked for any other than the West system, but may I suggest you look into Norglass products. They two fillers, one of them is Norfil which I used and it's extremely solid and tight. Well worth looking at in my opinion.