Barney12 Posted June 26, 2017 Share Posted June 26, 2017 I know there's a few boaty/planey (technical terms!) types on the forum so I had a quick question regarding bonding fibreglass to PVC pipe: As a general rule its supposed to be a "no" as fibreglass doesn't stick that well to plastics but in the past I have got away with it by roughing up the pvc and giving it a good clean with acetone. I've also used 3M 5200 in the past but it takes bloody days to dry properly and is a messy horrible product. I wondered if anyone had used any other methods? Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 26, 2017 Share Posted June 26, 2017 What situation is it to be used in? Penetration through a grp roof? Link to comment Share on other sites More sharing options...
Barney12 Posted June 26, 2017 Author Share Posted June 26, 2017 9 minutes ago, Nickfromwales said: What situation is it to be used in? Penetration through a grp roof? Yup! Well a GRP box gutter to be precise (Its still a concept idea at the moment but I'm working it up ) Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 26, 2017 Share Posted June 26, 2017 Ok. Opening going down into a PVC down pipe or other? Dont be shy Link to comment Share on other sites More sharing options...
Barney12 Posted June 26, 2017 Author Share Posted June 26, 2017 Just now, Nickfromwales said: Ok. Opening going down into a PVC down pipe or other? Dont be shy Yep. Going down into a PVC downpipe (but a 32mm standard solvent weld pipe, not a gutter downpipe) Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 26, 2017 Share Posted June 26, 2017 For rain water? Eg exposed to the elements? Link to comment Share on other sites More sharing options...
Barney12 Posted June 26, 2017 Author Share Posted June 26, 2017 Just now, Nickfromwales said: For rain water? Eg exposed to the elements? Yep rainwater. But not exposed as it will be behind a cladding detail. Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 26, 2017 Share Posted June 26, 2017 Ok, but 32mm is WAY small ??. Anyhoo, all you do is use a piece of said pipe to make a funnel out of the grp. Let it part set then remove it. Once the grp has set fully, push the pvc pipe on with Sikaflex EBT as the glue and your home and dry. ? Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 26, 2017 Share Posted June 26, 2017 Can't you use 40/42mm? That'd be way better. Link to comment Share on other sites More sharing options...
Barney12 Posted June 26, 2017 Author Share Posted June 26, 2017 1 minute ago, Nickfromwales said: Ok, but 32mm is WAY small ??. Thats the bit I'm working on. There wont be only one. My calcs suggest 3 should be sufficient for a 5mx2m flat roof. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted June 26, 2017 Share Posted June 26, 2017 I've made up a drain for a GRP roof, using a bit of GRP tube that fitted inside a standard 68mm down pipe. IIRC, I bought it from Cornish Fibre Sports, back when my cousin worked there. It was easy to just bond this in place, as it was shaped like a top hat, with a thin flange to bond the roofing on to. The down pipe just pushed up from underneath, over the stub. Link to comment Share on other sites More sharing options...
Barney12 Posted June 26, 2017 Author Share Posted June 26, 2017 7 minutes ago, JSHarris said: I've made up a drain for a GRP roof, using a bit of GRP tube that fitted inside a standard 68mm down pipe. IIRC, I bought it from Cornish Fibre Sports, back when my cousin worked there. It was easy to just bond this in place, as it was shaped like a top hat, with a thin flange to bond the roofing on to. The down pipe just pushed up from underneath, over the stub. Thats what I was looking for but I've not been able to find anything like it online. CFS don't list one. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted June 26, 2017 Share Posted June 26, 2017 (edited) I believe the TPE ones can be bonded to GRP OK: https://www.roofinglines.co.uk/product/roof-drain-tpe-63mm Here's confirmation that TPE is OK with GRP: https://www.roofingsuperstore.co.uk/product/roofdrain-outlet-tpe-60mm.html Edited June 26, 2017 by JSHarris 1 Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 26, 2017 Share Posted June 26, 2017 Bingo. Much easier ( and the leaf litter is far more likely to go down that unassisted ). Link to comment Share on other sites More sharing options...
Barney12 Posted June 26, 2017 Author Share Posted June 26, 2017 Do you reckon this one will shuv down a 32mm pipe? https://www.roofingsuperstore.co.uk/product/roofdrain-outlet-tpe-40mm.html Link to comment Share on other sites More sharing options...
Jeremy Harris Posted June 26, 2017 Share Posted June 26, 2017 I doubt it, but it might well fit in a 40mm waste pipe socket fitting. Link to comment Share on other sites More sharing options...
Russell griffiths Posted June 26, 2017 Share Posted June 26, 2017 I was going to come up with a few ideas but it looks like the other lads have it covered. What i I would say backs up nick in that your pipe is a bit small I wouldn't rely on doing some calcs on water volume common sense would dictate that any foreign debris will block that in a second, I would definitely use a larger pipe. Link to comment Share on other sites More sharing options...
SteamyTea Posted June 26, 2017 Share Posted June 26, 2017 You can get self etching polyester resins and there is a paint on liquid to help bonding to PVC (can't remember the name, it was a white coloured liquid, possibly a silane). If you try and bond to the internal surface of a pipe you will almost certainly have problems as the GRP will shrink while it cures. This may not be obvious at first, but it will in time. Also worth applying a gelcoat to the PVC first as this can allow for a better mechanical lock if the surfaces is scored (roughed up). It also allows the base resin to adhere better. Or you could apply a release agent to the inside of the PVC, then a gelcoat and a 'fast mix' for the layup. This will shrink away. Then you can release the pipe from the GRP, smear it with silicone sealant and reassemble. 1 Link to comment Share on other sites More sharing options...
Barney12 Posted June 26, 2017 Author Share Posted June 26, 2017 3 hours ago, Russell griffiths said: I was going to come up with a few ideas but it looks like the other lads have it covered. What i I would say backs up nick in that your pipe is a bit small I wouldn't rely on doing some calcs on water volume common sense would dictate that any foreign debris will block that in a second, I would definitely use a larger pipe. Ive been trying to come up with a hidden gutter design for my dormer. For it to work the outlet pipe would need to sit behind the timber cladding hence needing to try and keep the pipe diameter narrow otherwise the reveals on the windows will be deeper than I ideally want. Closing off the pipe entry in the hidden gutter is not hard with a bit of stainless mesh to prevent debris entering. However i cant convince myself of a satisfactory design.....yet! Link to comment Share on other sites More sharing options...
Barney12 Posted June 26, 2017 Author Share Posted June 26, 2017 I could run the drain pipe internally but as this is an "afterthought" I've got no means to connect the internal pipe to the storm drain run as I made no provision in the slab. I could connect it to it to the foul drain but if the BCO spots it I'll be in trouble as I'm fairly certain that's not allowed. Or is that only in the case of mains connected foul? (Mines a treatment plant). Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 26, 2017 Share Posted June 26, 2017 You wouldn't want the excess rain water constantly flowing into your plant, so it'll be YOU that's in trouble if you do . Link to comment Share on other sites More sharing options...
Barney12 Posted June 27, 2017 Author Share Posted June 27, 2017 8 hours ago, Nickfromwales said: You wouldn't want the excess rain water constantly flowing into your plant, so it'll be YOU that's in trouble if you do . Yes, I kinda thought that after I typed it Link to comment Share on other sites More sharing options...
Russell griffiths Posted June 27, 2017 Share Posted June 27, 2017 Any reason the pipe needs to be round? Why not a fibreglass rectangle 100 x32 would this fit in the batten area behind the cladding. Link to comment Share on other sites More sharing options...
Barney12 Posted June 27, 2017 Author Share Posted June 27, 2017 27 minutes ago, Russell griffiths said: Any reason the pipe needs to be round? Why not a fibreglass rectangle 100 x32 would this fit in the batten area behind the cladding. Now thats a very good idea! Link to comment Share on other sites More sharing options...
PeterW Posted June 27, 2017 Share Posted June 27, 2017 If it's not exposed to sunlight then ordinary rectangular extract duct would work - 220mm x 40mm would be easy to work with. Link to comment Share on other sites More sharing options...
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