Bl**dy Epoxy

[Babylon]

Yesterday I tried to use Blakes SP-106 epoxy resin to seal bare plywood in my engine bay. The stuff went properly syrupy in the mixing pot and stuck nicely to the vertical surfaces I was coating, but after a few minutes the coldness emanating from adjoining parts of the fibreglass hull cooled it down. It then started to liquify again and run down the plywood! I tried to warm it up with a fan heater, but it began to rain heavily so I closed the hatches. Despite wearing a proper vapour mask, stuck in a small boat crouched in the engine bay using a fan-heater like a hair-dryer on this noxious mix of chemicals, I started to go all dizzy.

The resin that had already dripped off the ply onto the cold GRP hull went even more runny, so I was using cloths to mop it up. Try as I might I couldn't heat the hull sufficiently with the fan-heater to get it to set. I then threw open the main hatch and burst out to get clean Southampton air into my lungs, but I had to make several more forays into the cauldron to ensure the epoxy on the plywood walls - if not the hull - had set. Eventually I packed my stuff and locked up the boat. Don't know what I'll find when I return in a few days....

 

[sailorman]

Yesterday I tried to use Blakes SP-106 epoxy resin to seal bare plywood in my engine bay. The stuff went properly syrupy in the mixing pot and stuck nicely to the vertical surfaces I was coating, but after a few minutes the coldness emanating from adjoining parts of the fibreglass hull cooled it down. It then started to liquify again and run down the plywood! I tried to warm it up with a fan heater, but it began to rain heavily so I closed the hatches. Despite wearing a proper vapour mask, stuck in a small boat crouched in the engine bay using a fan-heater like a hair-dryer on this noxious mix of chemicals, I started to go all dizzy.

The resin that had already dripped off the ply onto the cold GRP hull went even more runny, so I was using cloths to mop it up. Try as I might I couldn't heat the hull sufficiently with the fan-heater to get it to set. I then threw open the main hatch and burst out to get clean Southampton air into my lungs, but I had to make several more forays into the cauldron to ensure the epoxy on the plywood walls - if not the hull - had set. Eventually I packed my stuff and locked up the boat. Don't know what I'll find when I return in a few days....

why not use bilge paint

 

[caiman]

I've never had that problem myself.The epoxy I use goes thin when it's warm,not when it's cooled down.Also,the exoxy I use has little or no odour,you can use it indoors without gassing the whole house.I've just this morning ordered another 6KG which works out at about 6 litres of the stuff-£83 IMMSMC.They sell smaller quantities if required,also wood flour and silica powder.The lack of odour(solvent) is important to me as my workshop is in the celler.The supplier is 'Fyne Boats' in Cumbria-no connection except being a satisfied customer.The only drawback with this epoxy is that it is slow setting.It sounds as if maybe you have put your's on a bit thick?Have you got the mix percentage correct?Did you mix the two parts together properly?If you are lucky,you might be able to chip the epoxy runs off when they have set.It should set ok,so long as properly measured and mixed,even in these temperatures,if left for a couple of days.
Good luck.
Cheers

 

[Boathook]

I have never had that problem but the fact that it smelt strongly does not seem right. The only time the epoxy that I use smells is when the hardener is on the way out and it has gone a straw colour. Still works ok for non structual uses. Also colloidal silica is used to thicken the resin when used on vertical surfaces.

 

[DownWest]

About the hardener: I was told by the firm that discolouration to straw/brown does not effect it's qualities. Someone in the tropics told me that it is delivered that way to them and still lasts for years.
The OPs story sounds like the surface had something on it. Cold thickens the stuff. And the fumes do not make you dizzy, unless it is one of the solvent ones. SP 106 is not.

 

[Clyde_Wanderer]

Are you sure you are not using Polyester resins or is there any chance you have mixed in Acetone? as epoxy has a very mild sweat smell, certainly not a pungent smell or toxic as with polyester.
As others have said, epoxy remains quite viscous when cold and gets thinner as it warms up, you are better to warm the surface first then apply a light coat and when that starts curing (goes tacky) then apply the next coat and so on, this method works well especially on wood as the thinner first coat soakes into the warm wood making for better adhesion.
Usually epoxy is mixed at a ratio of 1 hardner to 5 resin, well for Wests systems anyway, I would imagine other systems would be similar.
C_W

 

[prv]

Usually epoxy is mixed at a ratio of 1 hardner to 5 resin, well for Wests systems anyway, I would imagine other systems would be similar.

Depends on the actual composition that the manufacturer puts together - some others are 2:1 and probably yet other mixes as well.

As long as it's not 50:1, in which case you probably have polyester instead

Pete

 

[Poignard]

None of my business really, but why do you think it is necessary to go to the expense and trouble of coating plywood around the engine bay with epoxy? Is it going to get wet or be exposed to an unventilated damp atmosphere? If so, wouldn't it be better to do something about that?

As Sailorman recommends - use bilge paint.

 

[Avocet]

I've used SP 106 quite a lot and I too am surprised about the fume problem. I've only used it outdoors though.

Unfortunately, epoxy is awful stuff for running. It's quite viscous but has absoluteoy NO surface tension. It also changes it's viscosity dramatically with temperature.

Using it on a vertical plywood surface, was the intention to get it to penetrate and seal the plywood, or just to act as a waterproof "paint"? If the former, all you can do is warm it before applying (so it goes really thin) and then apply it quickly in a VERY thin coat. I've almost "French polished" it on with a rolled up rag, rather than using a brush on occasions.

If you just want some coating on the ply and you don't want to sand it afterwards, mix a bit of colloidal silica into it. That stops it running quite so much, but it's damned hard to sand!

 

[Bobc]

For coating you should really use SP320 (used to be called Spacoat). 106 is more for bonding and filling.

 

[oldsaltoz]

You can get a very thin layer by applying the epoxy with a roller (much faster than a brush)and running a squeegee over the surface to thin out the layer. re-coat when tacky to avoid sanding between coats.

For small areas use a credit card.

If you warm the job the resin will thin out on application, if you warm the resin as well (stand the container in hot water it start to cure sooner rather than later.

Good luck.

 

[Babylon]

Using it on a vertical plywood surface, was the intention to get it to penetrate and seal the plywood, or just to act as a waterproof "paint"?

Thanks to all for the replies - I'm certainly reassured by the advice.

Perhaps the fumes were in my imagination. Over the years I've gradually become sensitised to fumes (and perhaps therefore a little irrational). I've long since taken to wearing respitory protection against wood-dust, adhesives and finishing products in my workshop; and I tend to switch the car air-con off or recirculate air when behind vehicles with diesel exhausts.

My reason for sealing the wood (and adjoining bits of built-in fibreglass) with epoxy, was that these are the areas that became badly saturated last summer with oil that had leaked into the engine bilge. The spillage was made worse by not having an extractor on board (or any access to the bilge under the old Bukh to mop the oil out) when finally moored outside Brixham in rough northerly conditions, when the oil sloshed up the turn of the bilge and heavily saturated the bare ply behind the side-panels, as well as running forward both sides of the cabin under the quarter-berth, fridge-box, chart-table, battery-box, cooker, galley, etc.

It's taken me over a month of work every weekend to first cut out access openings in the worst of the panels, then repeatedly clean with bilgex and flush out with water, followed by painting OT8 onto the worst affected areas and flushing and drying again. Last weekend - for the first time - I was able to open up the hatch and not be assaulted by any oil fumes.

My plan was to seal any remaining contamination in with epoxy (where I can reach), then paint with bilge-paint, before installing the new Beta engine.

Babylon

 

[Georgio]

Sounds to me like there is still some oil residue in the wood that will may epoxy coating difficult. As others have suggested I would go down the paint route.

 

[sailorman]

Sounds to me like there is still some oil residue in the wood that will may epoxy coating difficult. As others have suggested I would go down the paint route.

 

[Boathook]

Thanks to all for the replies - I'm certainly reassured by the advice.

Perhaps the fumes were in my imagination. Over the years I've gradually become sensitised to fumes (and perhaps therefore a little irrational). I've long since taken to wearing respitory protection against wood-dust, adhesives and finishing products in my workshop; and I tend to switch the car air-con off or recirculate air when behind vehicles with diesel exhausts.

My reason for sealing the wood (and adjoining bits of built-in fibreglass) with epoxy, was that these are the areas that became badly saturated last summer with oil that had leaked into the engine bilge. The spillage was made worse by not having an extractor on board (or any access to the bilge under the old Bukh to mop the oil out) when finally moored outside Brixham in rough northerly conditions, when the oil sloshed up the turn of the bilge and heavily saturated the bare ply behind the side-panels, as well as running forward both sides of the cabin under the quarter-berth, fridge-box, chart-table, battery-box, cooker, galley, etc.

It's taken me over a month of work every weekend to first cut out access openings in the worst of the panels, then repeatedly clean with bilgex and flush out with water, followed by painting OT8 onto the worst affected areas and flushing and drying again. Last weekend - for the first time - I was able to open up the hatch and not be assaulted by any oil fumes.

My plan was to seal any remaining contamination in with epoxy (where I can reach), then paint with bilge-paint, before installing the new Beta engine.

Babylon

Sounds like the ply is still contaminated with oil. Not to sure what OT8 is but that could cause problems as well. I would paint the wood rather than epoxy to let it 'breathe'. I suspect that oil may still leach out over the years lifting any finish.

 

[bluemoongaffer]

Epoxy fumes in confined spaces can be semi-harmful (if such a term exists). It sensitises the skin - particularly if you're light skinned / blond. It doesn't seem to do long term damage (I don't think / hope) but once you're sensitised it will keep coming back if you continue with prolonged glueing. Only solution is full throwaway suit (including hood as scalp can get very sensitive), carbon face mask and gloves.

Otherwise, I've found West to be more tolerant of minor mix variation / temp variation etc than SP. From bitter experience, I've found that a small amount of contamination or too low a temp with SP, can mean a lousy bond.

 

[Amulet]

Curing epoxy in the cold

Gougeon Brothers report - for West System - success down to 7 Celsius, though I think that's below the recommended minimum in the technical data sheets for the stuff.

That's consistent with my results (or lack of them). I did do some stuff on a dinghy at about 5 Celsius. It did not go hard, and even when subsequently submitted to Summer temperatures it remained sticky to the touch. It was inside a buoyancy compartment, so was not a day-to-day problem.

Careful if standing it in hot water - you can reduce the pot life to about 10 minutes if you overdo it.

My experience with coating is that even if you get the resin to about the right temperature, if you paint it on a cold substrate it cools down quickly enough to give problems. I.e., you have to heat the boat before you apply it - and thoroughly.