Ready Steady Eddy

[Neale]

I've used a fair bit of epoxy (usually thickened, though) for various boat repairs in the past and I can confirm that it is exothermic from personal experience. Fine in a wide, shallow, container but in a tall, narrow, container on a warm day - the pot was starting to smoke after a few minutes and it also starts setting much more quickly as it warms! For levelling, though, and assuming that it doesn't get too hot in the mixing pot, you are going to be putting a thin layer on a metal surface at ambient temperature so I doubt if temp will give problems; my guess is that viscosity is more important than setting time here, as long as it has time to run before it starts to gel.

As a solvent, epoxy resins don't seem to be as aggressive as, say, polyurethane resins. I used some small plastic pots for weighing out and mixing epoxy with no problem; first time I did the same with a 2-pack polyurethane, it went straight through the pot, the plastic tray I was using to catch the drips, and although the scales were metal and wiped clean, the stuff didn't do much for the plastic cover over the display which isn't quite so easy to read any more. My guess is that you are probably OK with the rubber sealing strip, but it would be easy enough to test a little bit first, maybe.

[FatFreddie]

I realise there will be some heat generated by the mix but do you think the draught excluded can retain it ?

A 5mm layer of epoxy isn't going to generate enough heat to warm up a big chunk of metal far enough to generate any problems. Don't wait too long before pouring it though as it will generate heat in the pot.

[Boyan Silyavski]

In fact when i mixed and poured the West System just 2 days ago, outside was around 19C. When i mixed it, for a second was a bit worried about the quantity i mix, but nothing happened. No heat at all.

Epoxy also suffers from humidity, i know this, as i live at 90% humidity near the sea.. So most epoxies i have used before/marine grade usually/ dried with a kind of mattish surface.

In the pdf says that the WS has no problem in high humidity working area.

[njhussey]

The epoxy came today, only ordered it yesterday...nice!! Anyway, got it out of the box and gave it a shake to see how viscous it was. Not too bad and should pour quite nicely. I'm going to experiment with a small bit of steel and see how it mixes and settles between a couple of channels.

[EddyCurrent]

Reactive Resins Syntac EPAFD epoxy with Synamin 201-c slow hardener.

This was the starting point using shims to level up the linear rail support beams.



A test piece was made using a 50x50 offcut, epoxy resin, draught excluder moat, http://www.toolstation.com/shop/Iron.../sd2802/p70101

Temperature 17 deg C
Used kitchen digital scales to measure out by weight.
Mixed in a plastic cup, no melting of cup, no heat felt but it was only a very small amount.

Just after pouring, the viscosity was very good for pouring, it seemed to be runnier once the hardener had been added and mixed.



You can see surface bubbles, I dragged a tooth pick/cocktail stick through the epoxy a few times and bubbles dispersed.
Next time I will mix the two parts more slowly so as not to introduce so much air.



The viscosity was such that 2 hours later the remains in the plastic cup could still move like a thick fluid.
Slight leakage occurred at draught excluder butt joints e.g. corners, so I will be using a dab of glue at these points.

Following day about 20 hours after pouring.



Depth of epoxy = 5mm
Draught excluder removed with a chisel no problem but it left a slight sticky residue that cleaned up okay with spirits and the epoxy captured a very small amount of foam in it's outer skin.
A slight meniscus can be seen but this was expected, 'Clive S' describes how best to remove this.
The epoxy is fairly hard but you can tell it has a day or two to go until it's cured.

I would say this test was a success and I have no problem with using this on the machine.

[cncJim]

Thanks for posting the pics eddy! The foam seems an excellent quick way to do this task.

... the epoxy captured a very small amount of foam in it's outer skin.

I wonder if applying some sort of grease to the draft excluder before pouring would help with that?

Jim

[EddyCurrent]

I wonder if applying some sort of grease to the draft excluder before pouring would help with that?Jim

Vaseline maybe (no jokes now!)

[Clive S]

You can see surface bubbles, I dragged a tooth pick/cocktail stick through the epoxy a few times and bubbles dispersed.
Next time I will mix the two parts more slowly so as not to introduce so much air.

Ready Steady Eddy-epoxy2.jpg

I found that a warm air gun flashed across the surface got rid of the bubbles. As a matter of interest the Wests System was still like thick water 6 or 7 hors after the pour before its started the cure. With no sticky stuff on the top when cured. Also the mixing was just done with a flat bit on thin ply and gently stirred it round. ..Clive

[EddyCurrent]

I found that a warm air gun flashed across the surface got rid of the bubbles. As a matter of interest the Wests System was still like thick water 6 or 7 hors after the pour before its started the cure. With no sticky stuff on the top when cured. Also the mixing was just done with a flat bit on thin ply and gently stirred it round. ..Clive

You mentioned this before so I tried a hair drier (it's the wife's, no use to me now) on it's lowest speed but it was moving the epoxy round like the seas at Cape Horn.
Yes I think this epoxy was still flexible after 6 to 7 hours but maybe just beyond any self leveling properties on the scale required.
It's interesting you confirm the slow mixing method.

[Clive S]

You mentioned this before so I tried a hair drier (it's the wife's, no use to me now) on it's lowest speed but it was moving the epoxy round like the seas at Cape Horn.
Yes I think this epoxy was still flexible after 6 to 7 hours but maybe just beyond any self leveling properties on the scale required.
It's interesting you confirm the slow mixing method.

I meant to say hot air gun straight after the pour so the waves won't matter. I was told by the people at Wests a good way would be to mix in a container with a small hole at the bottom on the side (say 7mm) with some tape over it, when mixed remove the tape and let the epoxy flow out of the hole into your trough that way you don't get the bubbles. I never tried though. ..Clive