mike morley Posted October 27, 2013 Share Posted October 27, 2013 I poured the initial layer of PVA "water" in my stream/ditch four days ago and about a quarter of it is still milky. I know I should I wait for it to clear completely before I pour the next layer, but the layouts first exhibition looms ever larger and I'm already starting to panic. Do I have to wait for the rest of it to dry before pouring further layers or can I get away with another layer now? Link to post Share on other sites More sharing options...
shortliner Posted October 27, 2013 Share Posted October 27, 2013 I'd leave it, and if the exhibition arrives before it gets poured again, if anyone comments say "there has been a drought and a hose-pipe ban is in force!" Link to post Share on other sites More sharing options...
mike morley Posted October 27, 2013 Author Share Posted October 27, 2013 The problem is not so much the dryness of the water (oxymoron?) as all the other things I am unable to do to the layout while I wait for the water to dry. I reckon two, more likely three layers more will be needed, factor in the certainty that temperatures will plummet very soon, slowing drying times even more, and . . . Yikes! Link to post Share on other sites More sharing options...
mike morley Posted October 30, 2013 Author Share Posted October 30, 2013 I'm reviving this barely-got-started-in-the-first-place thread (Thanks Mickey and Shortliner) because the situation has got worse and as PVA has become a popular means of reproducing water it could well affect others in the future. When I made the original posting the waterway concerned (A ditch/stream about four feet long) was about 80% clear, glossy, potential "water" with the rest obstinately refusing to look like anything other than half-dried pools of white PVA glue. That was when it had been down for four days Then the Great Storm happened and the weather conditions changed. It's now been down a week and only 20% of the watercourse is clear, glossy, potential "water" while the rest - including, obviously, an awful lot that was perfectly satisfactory before - has become opaque and milky. A couple of cautious prods, followed by some rather sterner taps with a fingernail has established that the whole lot has set as solid as a rock. Comments, anyone? Link to post Share on other sites More sharing options...
corax67 Posted October 30, 2013 Share Posted October 30, 2013 As much as I hate to be a harbinger of doom but what you currently have is officially a lost cause. Your original areas of milky PVA are due to it having been applied too thickly in places and surrounding thinner patches drying around it, trapping moisture and encapsulating it never to fully dry and always remain milky. Unfortunately though it sounds like all of the PVA in your watercourse was not 100% set when the weather changed and it sucked in moisture from the damp air dramatically increasing the milky appearance of your water. Had this on a club layout when we poured a canal basin scene and the solutions are fairly dramatic unfortunately. Options: remove all the PVA you have already poured (chisel, scraper, etc) and start again brushing thin layers of PVA whilst running some form of heating to ensure adequate drying (space heater or fan heater) paint over what has been poured to create a new riverbed and then brush thin layers of PVA with heating on to set. I understand the exhibition deadline and the need to expedite the situation but If you pour to speed up the process you are going to end up with milky spots again - sorry Link to post Share on other sites More sharing options...
mike morley Posted October 30, 2013 Author Share Posted October 30, 2013 Thank you, Corax. The same diagnosis has been lurking in the back of my mind for the last few days but I've been in denial, needing the confirmation you have provided. Ironic that a mainly winter-based hobby features something central to many layouts that is best suited to being done in high summer! Link to post Share on other sites More sharing options...
BG John Posted October 30, 2013 Share Posted October 30, 2013 If it's urgent, can you redo it as a dry stream/ditch, and add the water after the exhibition when you can take your time? The streams through my land (in real life) have been dry all summer, with just some small ponds in the deeper bits, before reverting to raging torrents recently! Link to post Share on other sites More sharing options...
mike morley Posted October 30, 2013 Author Share Posted October 30, 2013 Thanks, John The situation isn't that desperate. Its a case of I cant do Job A until I've done Job B, which I cant do until I've done Job C etc. The watercourse is probably only Job K or L but is the log-jam that's holding everything else up so is causing the panic. Dry streams in West Wales? We are talking about the same Wales here, are we? Link to post Share on other sites More sharing options...
cromptonnut Posted October 30, 2013 Share Posted October 30, 2013 I would personally start again and use one of the resin water products such as the Woodland Scenics one. Obviously it smells worse than pva but sets a lot quicker and efficiently. Link to post Share on other sites More sharing options...
mike morley Posted October 30, 2013 Author Share Posted October 30, 2013 As it happens, it was a false start with Woodlands Scenics that prompted me to use PVA in the first place. I found it was so thick and gloopy it was quite difficult to work in the first place and its ultra-slow setting time caused further problems. I could set everything up as best I could before leaving it to set then come back a couple of hours later to find nothing obviously amiss, I could then return next morning to find the baseboards had evidently been a fraction of a degree or so off dead level and the gloop had spent the night oozing slowly down the gradient, solidifying as it went, to produce a ridiculous-looking watercourse of the type that prompted dubious jokes about Irish water-skiers. If anyone wants an extremely expensive, almost-full bottle of Woodlands Scenics allegedly Realistic Water . . . Link to post Share on other sites More sharing options...
RMweb Gold gwrrob Posted October 30, 2013 RMweb Gold Share Posted October 30, 2013 Thats how my bit of estuary came out after a few coats....apologies to anyone (everyone?) thats seen that shot before pva water.jpg If you've got some spare time you're welcome to finish mine Mickey. Link to post Share on other sites More sharing options...
RMweb Gold gwrrob Posted October 30, 2013 RMweb Gold Share Posted October 30, 2013 Ill swap a bit of sea for Brent! Ok which bit. Seriously that's just the effect I'm and the OP's after I think but it's not a quick job and it certainly needs to be warm when you attempt it otherwise it goes cloudy. Link to post Share on other sites More sharing options...
corax67 Posted October 30, 2013 Share Posted October 30, 2013 Under warm conditions you can get thin coats of PVA to set within an hour ready to brush on the next - it's the last dozen layers which need extra time and attention to give the best finished water surface. Link to post Share on other sites More sharing options...
mike morley Posted October 30, 2013 Author Share Posted October 30, 2013 Its the thinness of the PVA coats that seems to make the difference to the drying time.....I really do mean thin! Define thin, please. Do you mean fractions of a millimetre or well diluted? Link to post Share on other sites More sharing options...
BG John Posted October 30, 2013 Share Posted October 30, 2013 Dry streams in West Wales? We are talking about the same Wales here, are we? I should have taken photos to prove it! I now discover that only 21 years after inheriting them from my Dad, I have a leak in one of my wellies!!!! Link to post Share on other sites More sharing options...
corax67 Posted October 31, 2013 Share Posted October 31, 2013 Define thin, please. Do you mean fractions of a millimetre or well diluted? When I say 'thin' I mean literally brushed on as if it were a coat of acrylic paint or emulsion on a wall, almost opalescent in look. It's a laborious process but a whole lot better than having to dig out & rework. Link to post Share on other sites More sharing options...
raymw Posted October 31, 2013 Share Posted October 31, 2013 Hi Mike, depending on the era that you are representing, you could put on a few dead fish and a factory with a waste pipe pumping into the stream, or turn it into a temporary green lane with some added debris and a landrover.(If after 1950). Best wishes, Ray Link to post Share on other sites More sharing options...
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