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robenergy
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Hey, Thanks for popping in and having a look at the post. So my first ever resin infusion project has almost got to the stage where I'm ready to do the lay up! And yes, for a first project I may have gone off in the deep end!! It's certainly taken longer to complete and had more headaches than what I was expecting!!lol I've put together a couple of crude drawings of my molds, if somebody could have a look at the attached pictures and let me know how best to lay this up, in particular, if you could point out where best to put the spiral tube and infusion/vacuum points, and suggest what size spiral tube/infusion connectors to use for the base (pic 1), would be great. And if you could point out where best to put my spiral tube and infusion/vacuum points on the main tub (pic 2), that would be great too. I just hope I haven't limited myself too much!? Pic 1  Picture 1 is of the mold for the base. Material and consumables will be applied to the inside of it so that the outside of the base is against the mold. And it will probably be used upside down? I just hope my flanges are wide enough to put the tape for the bag and infusion valve!? Pic 2  Picture 2 is of the mold for the main tub of my bath. Material and consumables will be applied to the outside of it so that the inside of the tub is against the mold and everything will be pulled down around it. I did ask somebody else and they suggested I have my infusion point at the plug/drain hole with the spiral tube reaching out half a meter either side of it. But wouldn't this approach get in the way of the vacuum bag pulling down materials over the plug hole properly? My original idea was to have an infusion point on one corner and a vacuum point on the other corner? Also, I have these 2 plastic infusion connectors to fit 1/2" spiral tube to be used on the mold for the tub, what I'm not so sure about is, the black one doesn't have any channels molded into it for the spiral tube, do I screw in 4 screws to act as spacers and create a half inch gap underneath that way for the spiral tube, or do I find a milling machine??  I hope all this makes sense. Thanks for your time! Rob
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MarkMK
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Hi Rob As a basic rule of thumb, you want to choose the locations with the shortest distance between your inlet and outlet hoses. On something like a bathtub shape, that looks like it would be halfway down each of the long straight sides. Even then, there's likely to be a fair distance between the two, so running your infusion spiral so it runs along the inlet straight edge and halfway around the curve at each end will help spread the resin fairly evenly. It might also help to lay down some additional strips of infusion mesh at the most distant points from the inlet to help things flow better. By doing so, you'll create channels where there's a double layer of mesh and this will help the flow keep up with the shorter section at the middle. It'll mean using a little more resin but it should, hopefully, help to ensure all areas are thoroughly wetted-out by the time the resin reaches the exit port. I'd probably apply the same principals to both moulds. It looks like you'll need some fairly big pleats on the main tub mould also, to overcome the sheer height of the it so don't skimp on the bagging film, as it will increase the chances of leaks occurring if the bag is overly stretched when pulled down. Assuming that your bag has plenty of slack in it, pull things down fairly slowly, to help avoid the fabric becoming crimped are the highest extremes where the mould curves down. If necessary, put relief cuts in the mesh to help it lay down fairly flat, as crimps and creases here can transfer to your fabric and leave visible signs on the surface of the laminated part. Cut the mesh from the exit side, though, as you don't want to create zones around the inlet where the mesh is no longer joined together, as this will choke the flow of resin and slow things down in places. Another option is to place the inlet in the very centre of the tub and run the spiral to both ends, but there's always a chance of 'print-through' from the connector and spiral to the surface of the part unless you've got access to resin runners that are made for this type of approach. You'd also need to install two vacuum ports, one at each side that are both connected to your pump. This might feel a bit complicated if it's your initial project, though. I'm not overly certain regarding your connectors. The white one looks like it'll work okay on the inlet side, but the black might only work well for the vacuum line.. Perhaps putting a few layers of breather fabric underneath it before placing it on your strip of infusion mesh (for your resin break) will help make sure it pulls air okay without restriction.
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Zorbit
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Is that a plug hole in the centre of the bottom face ? If so, including an airline fitting, plugged with wax, will make demoulding easier.
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robenergy
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+xHi Rob
As a basic rule of thumb, you want to choose the locations with the shortest distance between your inlet and outlet hoses. On something like a bathtub shape, that looks like it would be halfway down each of the long straight sides. Even then, there's likely to be a fair distance between the two, so running your infusion spiral so it runs along the inlet straight edge and halfway around the curve at each end will help spread the resin fairly evenly.
It might also help to lay down some additional strips of infusion mesh at the most distant points from the inlet to help things flow better. By doing so, you'll create channels where there's a double layer of mesh and this will help the flow keep up with the shorter section at the middle. It'll mean using a little more resin but it should, hopefully, help to ensure all areas are thoroughly wetted-out by the time the resin reaches the exit port. I'd probably apply the same principals to both moulds. It looks like you'll need some fairly big pleats on the main tub mould also, to overcome the sheer height of the it so don't skimp on the bagging film, as it will increase the chances of leaks occurring if the bag is overly stretched when pulled down. Assuming that your bag has plenty of slack in it, pull things down fairly slowly, to help avoid the fabric becoming crimped are the highest extremes where the mould curves down. If necessary, put relief cuts in the mesh to help it lay down fairly flat, as crimps and creases here can transfer to your fabric and leave visible signs on the surface of the laminated part. Cut the mesh from the exit side, though, as you don't want to create zones around the inlet where the mesh is no longer joined together, as this will choke the flow of resin and slow things down in places.
Another option is to place the inlet in the very centre of the tub and run the spiral to both ends, but there's always a chance of 'print-through' from the connector and spiral to the surface of the part unless you've got access to resin runners that are made for this type of approach. You'd also need to install two vacuum ports, one at each side that are both connected to your pump. This might feel a bit complicated if it's your initial project, though.
I'm not overly certain regarding your connectors. The white one looks like it'll work okay on the inlet side, but the black might only work well for the vacuum line.. Perhaps putting a few layers of breather fabric underneath it before placing it on your strip of infusion mesh (for your resin break) will help make sure it pulls air okay without restriction.
Hi Mark, Thanks for the reply! If I was to go the route of putting my inlet in the centre of the mold, in the plug hole with resin runners extending out, any print through would be on the base of the bath and out of sight which would be fine obviously, my only concern is would the material get pulled down over the plug hole where the resin runner/spiral tube lays? PS, I've never seen or used a resin runner. But this method does sound like the better one I think. Relief cuts are an excellent point thanks, they will definitely be needed! I may even do certain parts of it in sections. If I have my vacuum points on the 2 corners, would it be worth doubling up in the infusion mesh on the opposite sections to where the vacuum points are in the actual tub do you think? Or would a few strips of it suffice? Also, what size spiral tube would be best for the mold of the base?? Thanks for your time! Rob
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robenergy
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Group: Forum Members
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+xIs that a plug hole in the centre of the bottom face ? If so, including an airline fitting, plugged with wax, will make demoulding easier. Hey Zorbit, Thanks for your input, another great point! Yes, its the plug hole in the centre of the bottom face. Would just normal wax be ok or should I be looking for a particular sort? Would modelling clay be good to use instead? Thanks for yor time! Rob
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Zorbit
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I have used cheap airline fittings, bunged up with filleting wax. After moulding, dig out the wax with a stick, attach an airline and gently turn on the air, this helps separate a deep sided mould. Take it gently though, don't just shove 100psi into it, give it time to work.
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robenergy
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Group: Forum Members
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+xI have used cheap airline fittings, bunged up with filleting wax. After moulding, dig out the wax with a stick, attach an airline and gently turn on the air, this helps separate a deep sided mould. Take it gently though, don't just shove 100psi into it, give it time to work. Filleting wax, that's the stuff thx..!  And yes, the air line definitely helped when I separated the plug n mould.. Now for the next stage..! Also, I'm right in thinking resin runners are the same thing as the spiral tube yes..?:p Thanks for your time Rob
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MarkMK
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If you're planning to use, say, a single 200g surface layer combined with a heavier fabric like a 600/650g, it's most likely that any print-through will be limited to the the resin inlet fitting as the narrower type of resin spiral akin to what EC sell probably won't print through. So, you could indeed try running the spiral across the centre length of the tub mould. In that scenario, it might be worth installing two vacuum ports, at the centre points either side, but be aware that the resin will likely reach these before wetting out the end sections ensure that resin breaks are used here to slow things down here and allow time for the ends to wet-out. Make sure that you have a narrow strip of mesh running all the way around the edge of your flange to allow any de-gassed air to reach the vacuum lines as things infuse. As the plug hole section will be raised, you'd again need to ensure that the bag was sufficiently large to pull down in this area without bridging and creating resin-rich corners around the inlet that will, most likely, be prone to breaking off, especially on a new mould where things will likely be a bit more tough to de-mould cleanly I'd likely look to cover the plug hole section with small sections of fabric, with relief cuts made in the main fabric section to slip over the hole. Done neatly, any join lines should be barely visible If going down the route of placing both inlet and outlet on the flange, though, I'd still avoid picking the corner to corner route, as this looks to be the furthest and could takes ages to wet out fully and make controlling the flow more problematic. Pay attention to pot life and temperature of your resin/mould in all instances as it will impact greatly on the speed at which things infuse.
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