PenrithBeacon Posted May 6, 2016 Share Posted May 6, 2016 I've just bought several sheets of foamboard from HobbyCraft. I was recommended to use Copydex as an adhesive. Is this correct, can anyone recommend an alternative? Regards Link to post Share on other sites More sharing options...
devondynosoar118 Posted May 6, 2016 Share Posted May 6, 2016 I like both UHU POR and Deluxe Materials Rocket Card glue for foam board. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted May 6, 2016 Share Posted May 6, 2016 I have never used anything but regular PVA from a squeezy dispenser bottle. Plenty of adjustment time, very strong once gone off. Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted May 6, 2016 RMweb Gold Share Posted May 6, 2016 I use pva - which doesn't seem to be quite so good in sheer with a heavy load on foamboard - or a hot glue gun (which has a major disadvantage of bonding like solid rock make it very difficult to alter things should you want to do so at a later date. Incidentally one trick I have used withe pva is to apply pin the sheets of foamboard together with panel pins while the glue goes off. Link to post Share on other sites More sharing options...
D9502 Posted May 6, 2016 Share Posted May 6, 2016 Hello I've used foam board as a 'core' for the inside of large 4mm buildings and as a box for making polyurethane moldings and use Copydex as the glue. I was told as long as you use a non solvent based adhesive you'll be OK because a solvent based adhesive will dissolve/melt the foam core. Copydex whilst not cheap compared to PVA forms a strong bond that doesn't deteriorate over time, some of my structures are nearly ten years old and still together fine. Copydex takes several minutes before starting to bond (depending on the surface area of the joint) so it allows you time to align everything together, the only downside being it smells funny and the small pots have a definite shelf life. Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted May 6, 2016 RMweb Premium Share Posted May 6, 2016 Having bought quite a few sheets of the A1 foamcore boards from Hobbycraft when they were on special offer with which to make baseboards, could I suggest that you are very careful with which type of glue you use, should you have a need to layer the boards for strength in any sizeable area. My first attempt used Hobbycrafts own 'school glue pva', and caused extreme warping of the boards. Wickes own pva seemed better, but I found that Anitas tacky pva in thin lines was the only way to get flat and stable results, covering the whole board surface seeming to cause shrinkage. I don't know if this is a common problem as the surface finish of foamcore boards appears to vary quite a bit with different types and qualities of finish I have since discovered. Izzy Link to post Share on other sites More sharing options...
alant Posted May 6, 2016 Share Posted May 6, 2016 I use foamboard for 7mm scale buildings and now glue together with Evo Stik Serious glue. I have also used a hot glue gun but you only get one chance to line things up! Link to post Share on other sites More sharing options...
mike morley Posted May 6, 2016 Share Posted May 6, 2016 I've used a hot glue gun but it isn't suitable for all types of joint - the heat doing nasty things to the foam core if the glue comes into contact with it. PVA and Copydex have also been used for joints where "instant grab" isn't needed. Totally agree with the Stationmasters comments about pinning joints. One thing I have found that has made me a bit wary of foamboard for "structural" applications is that it can warp, and quite a lot if it feels like it. Link to post Share on other sites More sharing options...
cessfordalan Posted May 6, 2016 Share Posted May 6, 2016 Good afternoon I use ordinary PVA glue from our local builders merchants without any problems and I also seal the form edges with PVA in case of overspill from solvent adhesive. No problems as yet touch wood Alan in the sunny and hot Outer Hebrides Link to post Share on other sites More sharing options...
PenrithBeacon Posted May 7, 2016 Author Share Posted May 7, 2016 Many thanks to all for the replies. The intention here is to make a test track that has the potential to be upgraded to a layout, but right now I need a test track. I thought that layering three sheets (while overlapping the joints) to make the top would do and then having verticals underneath to strengthen the upper surface and stop warping. The joints between the upper surface and the underneath verticals will by supported by fillets, ie strips of board into the joint, again overlapped. Comments welcome. Regards Link to post Share on other sites More sharing options...
peter220950 Posted May 7, 2016 Share Posted May 7, 2016 Many thanks to all for the replies. The intention here is to make a test track that has the potential to be upgraded to a layout, but right now I need a test track. I thought that layering three sheets (while overlapping the joints) to make the top would do and then having verticals underneath to strengthen the upper surface and stop warping. The joints between the upper surface and the underneath verticals will by supported by fillets, ie strips of board into the joint, again overlapped. Comments welcome. Regards Sounds interesting David, If you get the chance keep us informed of progress. - It might be worth putting a thin ply edge around the boards to prevent damage from handling. Peter EDIT P.S. I would also keep the top surface flat under some sort if board while it dries to prevent any curling. One of the things I found with foamboard and styrofoam is that it takes a long time for adhesives to set deep into the joints. Link to post Share on other sites More sharing options...
RMweb Gold ROSSPOP Posted May 7, 2016 RMweb Gold Share Posted May 7, 2016 Hi Just to say that I am experimenting with 5mm thick foam board. I did consider making a modular layout made entirely of the stuff. But other peoples experienced advise using wood and ply as strengtheners. Anyway, I have used a quality PVA (and plenty of it) to glue a layer over ply and then another 5mm layer as a track underlay so to speak....all for 7mm modelling. It does warp when the PVA is applied so weighting down until thoroughly dried is a must. I laid it this time last year, so its been in an unheated shed through winter...... so far no problems. I have primed the top layer with PVA to prevent problems with ballasting.....I hope. Regards Link to post Share on other sites More sharing options...
peter220950 Posted May 7, 2016 Share Posted May 7, 2016 I have primed the top layer with PVA to prevent problems with ballasting.....I hope. Regards DSC02276.JPG That looks very nice, did you prime the other side of the board as well to 'balance' any stresses? - I would have, but if you haven't it looks like it's not necessary. What's the stiffening grid spacing/depth? I have a 'new' layout floating around in the back of my brain, for which I was going to use 3mm laser cut mdf boards, but foam core is a possibility that your example has brought into the equation. Peter Link to post Share on other sites More sharing options...
RMweb Gold ROSSPOP Posted May 7, 2016 RMweb Gold Share Posted May 7, 2016 Yes Peter I primed both sides. The four units vary in length the longest is 4feet and , two at 3` 6`` and one at 2feet, width is 2` 3`` i`ve also experimented with using cheap superglue to fix the ballast at the baseboard joins....... jury still out on that isea though..... John Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted May 7, 2016 Share Posted May 7, 2016 The intention here is to make a test track that has the potential to be upgraded to a layout, but right now I need a test track. I thought that layering three sheets (while overlapping the joints) to make the top would do and then having verticals underneath to strengthen the upper surface and stop warping. The joints between the upper surface and the underneath verticals will by supported by fillets, ie strips of board into the joint, again overlapped. Don't laminate! Follow engineering practise in steel, apply verticals a seventh the depth of the span, running underneath where the load is applied. You will get way greater stiffness from the same material. I have trialled the making of a lift out access in 6mm foamboard on this principle, and found that 6" deep verticals under each pair of OO tracks, will adequately bridge a 42" gap. The two verticals had a foamboard base making a closed box 5" by 6" in end elevation. By occupying the track base with sixteen cans of baked beans distributed - representing an improbable arrival of all the heaviest traction on the four tracks of the bridge simultaneously - it deflected 2mm at centre under this load. In the final build I will add cross stringers an inch deep under the tracks, and gussets outside the box, both at 6" intervals, to stiffen the track base. The joy of this material is that it is cheap enough to do such experiments to edge toward a 'strong enough' solution. I was taught 'lightest structure' by a one time de Havilland airframe designer. Make it too weak, test it, and upgrade the strength only where necessary until just strong enough for acceptable deflection at the maximum applied load. Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted May 7, 2016 RMweb Gold Share Posted May 7, 2016 Many thanks to all for the replies. The intention here is to make a test track that has the potential to be upgraded to a layout, but right now I need a test track. I thought that layering three sheets (while overlapping the joints) to make the top would do and then having verticals underneath to strengthen the upper surface and stop warping. The joints between the upper surface and the underneath verticals will by supported by fillets, ie strips of board into the joint, again overlapped. Comments welcome. Regards I'm not clear what it would sit on underneath the verticals but the method should present no problems judging by my experience. I decided to add a shunting puzzle (not very puzzling alas) on top of my Taunton module and built the whole structure and 'baseboard' for the shunting area out of foam board. It part sits on the previous 'spine' (vertical foamboard) you can see in the first pic as it looked after I'd cut off the previous scenic top. Thus one side was well supported but as the 'baseboard' was to be much wider it is simply supported by pieces of foamboard arranged as vertical struts - some of which can be seen in the second picture. Some of the top is three layers of foamboard and some is just two layers. As constructed it seems perfectly stable and stands up to a bit of punishment - it has done several hundred miles to & from Taunton (twice) in the back of the car; has had occasional knocks passing through doorways and the 3 layer area has been inadvertently lent on by my elbows on a couple of occasions with no visible damage. It hasn't been out for a couple of years but there is no apparent warping or any other problems and it lives in an unheated, but well insulated, garage room. The track laying 'weight' in the third pic is in the area which is solely supported by vertical 'struts' of foamboard. Link to post Share on other sites More sharing options...
PenrithBeacon Posted May 7, 2016 Author Share Posted May 7, 2016 Don't laminate! Follow engineering practise in steel, apply verticals a seventh the depth of the span, running underneath where the load is applied. You will get way greater stiffness from the same material. I have trialled the making of a lift out access in 6mm foamboard on this principle, and found that 6" deep verticals under each pair of OO tracks, will adequately bridge a 42" gap. The two verticals had a foamboard base making a closed box 5" by 6" in end elevation. By occupying the track base with sixteen cans of baked beans distributed - representing an improbable arrival of all the heaviest traction on the four tracks of the bridge simultaneously - it deflected 2mm at centre under this load. In the final build I will add cross stringers an inch deep under the tracks, and gussets outside the box, both at 6" intervals, to stiffen the track base. The joy of this material is that it is cheap enough to do such experiments to edge toward a 'strong enough' solution. I was taught 'lightest structure' by a one time de Havilland airframe designer. Make it too weak, test it, and upgrade the strength only where necessary until just strong enough for acceptable deflection at the maximum applied load. Ok don't laminate; but ... The chances are that I will need an upper surface (for want of a better phrase) that is made of two boards in length. Whether they are two complete boards is another matter, it all depends what I can get into the car to transport the 'test track/layout' around. I haven't yet decided on the track layout and I was planning to do some experiments/explorations after the fashion of Iain Rice in his 'Wild Swan' book to decide. I've already got two C&L turnouts in stock and the S4/EMGS Manuals provide some other templates that can be photocopied, cut-up and generally buggered about with. I don't intend to go down the Templot route, it's far too difficult to learn (tried that already a few years ago) and at the age of 72 this will be, I'm pretty certain, the first and only 'test track/layout' I will attempt. So the plot is to work out a track layout first and then use that to inform the position of the under supporting members. I don't want to put a piece of structural material right where a point motor should go. The outside will be a skirt of marine ply which should provide some protection against warping, but then it probably won't be going that fast. Thanks again for the replies, most welcome. Regards Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted May 7, 2016 RMweb Premium Share Posted May 7, 2016 I have just about completed a small P4 'test track' layout using a mix of foamcore and mountboard in a layer sandwich. It is 60"x10" and 6"deep, being a simplified single board version of a similar but slightly larger folding baseboard P4 test track layout built in the mid 1980's. The construction mix was an attempt to add some structural strength as has already been stated foamcore board alone can warp quite badly given half a chance and I wanted minimum depth for lightness, storage, and ease of moving about. It weighs in at about 4Kg with a cover made from single layer foamcore. I'll try and find a couple of shots to post in case it might be of help or interest in giving anybody some ideas they can use. Izzy Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted May 8, 2016 RMweb Premium Share Posted May 8, 2016 Found some shots, hope they are of use. Mostly self explanetary. Wiring is in a recess under the middle of the board covered by a removable panel. Self-adhesive felt pads underneath protect what it is placed on. Points worked (via DPDT sliders) by brass wire running in slots cut in the cork. Although it is also liable to damage mount board is used as a cover layer over some exposed edges because it's a bit more resilient than plain foamcore. Edges of either can be covered in strips of say, plain 90gsm ink-jet paper glued on, and then painted over as well, emulsion, poster paint, etc. for extra strength. Doesn't always look pretty, but when it's for purely personal home use I don't worry too much. All the buildings are printed card (mountboard cores), the overbridge being used as a carry handle when moving the exposed layout around. Haven't quite finished painting the rear bits and putting all the static grass on yet. A very small layout, but quite a bit of fun to make and use. Izzy Link to post Share on other sites More sharing options...
PenrithBeacon Posted May 8, 2016 Author Share Posted May 8, 2016 Found some shots, hope they are of use. Mostly self explanetary. Wiring is in a recess under the middle of the board covered by a removable panel. Self-adhesive felt pads underneath protect what it is placed on. Points worked (via DPDT sliders) by brass wire running in slots cut in the cork. Although it is also liable to damage mount board is used as a cover layer over some exposed edges because it's a bit more resilient than plain foamcore. Edges of either can be covered in strips of say, plain 90gsm ink-jet paper glued on, and then painted over as well, emulsion, poster paint, etc. for extra strength. Doesn't always look pretty, but when it's for purely personal home use I don't worry too much. All the buildings are printed card (mountboard cores), the overbridge being used as a carry handle when moving the exposed layout around. Haven't quite finished painting the rear bits and putting all the static grass on yet. ... A very small layout, but quite a bit of fun to make and use. Izzy Brill! Something like I want to do but longer. Thanks for that, much appreciated. Regards Link to post Share on other sites More sharing options...
PenrithBeacon Posted May 21, 2016 Author Share Posted May 21, 2016 Current state of play Link to post Share on other sites More sharing options...
PenrithBeacon Posted May 21, 2016 Author Share Posted May 21, 2016 An earlier shot Alla bit rough and ready , I'm no craftsman! Link to post Share on other sites More sharing options...
PenrithBeacon Posted May 21, 2016 Author Share Posted May 21, 2016 To continue, I've found that the gussets need to be screwed and glued to the valances I'm using no6x1/2" philips head countersunk. Regards Link to post Share on other sites More sharing options...
PenrithBeacon Posted May 21, 2016 Author Share Posted May 21, 2016 Showing outside of valance. Board has an astonishing ability to warp without them. Needs holding down firmly, I use packs of birdseed! Link to post Share on other sites More sharing options...
PenrithBeacon Posted May 25, 2016 Author Share Posted May 25, 2016 The board is now finished, thanks to all who advised. A few lessons were learnt. 1 use the pva direct out of the bottle and don't let it down with water. 2 panel pins are of no value. 3 no4 woodscrews don't have enough of a thread to hold foamboard but no6 are fine 4 pva won't hold the cut ends of the board screws are needed too. Hope that helps somebody for the future. Regards Link to post Share on other sites More sharing options...
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