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TURK
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Excellent link that 'Freemansupply' Fred ........ many thanks. I had seen some of their how-to videos on youtube, but some of their articles are very good. TURK
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fgayford
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TURK (20/01/2016)
Hi folks, As per the thread title ........ I'm not sure if what I have bought from EC will be fine for what I am trying to accomplish. I purchased some 'Vac-Cast' Epoxy casting resin as I read it was ideal for a tooling plug as it was an aluminium filled epoxy casting resin resistant to heat. I've searched on the forum on how to use it ( and on YouTube ), but can't find anybody that has used it ! I did find however, many casting tutorials on the net but they were for liquid Latex and others. Am I to assume it's exactly the same procedure ? I have also read some of the tutorials on here, but the guide very quickly deviates to mould construction for the use of vacuum infusion for carbon fibre parts. I simply need to pour the mixture into a vacuum formed part. Leaving me with a 'male' plug so I can vacuum form many other parts just like my original. Any information greatly received as I'm really stuck as to which direction I need to go.
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TURK
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Group: Forum Members
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Hi Matt, Apologies if the last posts sounded a little sarcastic or even rude, wasn't my intention ........ just getting a little frustrated that's all. Many, many thanks for all the your answers, they've answered all my queries, and some. And I'm also an idiot ! ......... but you picked-up on that, as I did mean 'Vac-Cast Epoxy Resin' ! Actually, it's good news that the epoxy resin sticks to wood. I'll try and explain what I mean by that, and maybe it'll help other people out when constructing mould boxes. Originally my idea was to construct a mould box, like any mould box, giving me adequate space between my plug and the mould box sides, 18mm is what I had, as in the photo on the previous page. But then I had a better idea ........ what if I reduced the mold box size giving me a 9mm thickness to my resin mould, but leave the wooden sides on the mould. So I chose to make the mould box sides out of 9mm MDF, this stills give a mould with 18mm thick walls, strong enough to withstand most day to day handling and a vacuum forming machine. As the epoxy resin will stick to the wood I won't treat the sides with a release agent for better adhesion to the MDF. The base of the mould I chose to use 15mm melamine, and will be waxed and treated with mould release. As the base of the mould box definitely needs to release as it's in effect the top of my mould when I release it, and flip it over. The final 'tooling' mould I end up with should be a female mould. I'll just have to drill some holes in the bottom of it for vacuum release. Many thanks for clearing up the mixing ratios, I did do a little research on that but just needed confirmation. I'm pretty knew in this game and it's a steep learning curve, mistakes can be costly ! The reason why I need to know very accurately just how much resin and catalyst I'll be needing is, I live in France and don't think you can ship more Vac-Cast Resin to me as the catalyst is corrosive. With only one 5Kg bucket I may just have enough to complete my moulds. Anyway, thanks Matt. PS; thanks for the link ....... no doubt that will come in handy someday ; ) TURK
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Matt (Staff)
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Hi TURK, Sorry for the delay in getting back to you but I won't always be the quickest to respond to technical support issues due to the daily routines of running the business. Our technical support guys can be emailed directly on technical@easycomposites.co.uk and they will always get right back to you. In response to your questions; will pattern coat primer stick to wood ? Yes, Pattern Coat Primer will definitely stick to wood. Pattern Coat Primer is, essentially, a polyester resin. If you have any experience of polyester resins then you'll know that they will soak into and bond well to wood, Pattern Coat Primer is no different. However, looking at your post, I'm not sure that you actually mean Pattern Coat Primer. I think you might mean the Vac Cast Epoxy Casting Resin; this is a totally different product although the answer would be the same because Vac Cast is an epoxy and epoxy also sticks to wood. If I 'block-out' the underside of the resin mold with wood to save on resin, will I be able to remove the wood block once the resin has cured ? Yes, as mentioned above, the epoxy resin of Vac Cast would also stick to wood. To prevent the Vac Cast from bonding to the wood you could go for a basic (but fairly reliable) method of wrapping the wood with brown parcel tape. This type of tape is usually polypropylene and if it is then the epoxy won't stick to it. You can test a small area first to make sure. If you want a more professional approach then you could wrap the wood in Unperforated ETFE Release Film which the resin certainly won't stick to. Also, the pattern-coat primer and hardener is a 100:6 mix ratio - what does that mean ? Again, I'll assume you mean Vac Cast (not Pattern Coat Primer which uses MEKP as a catalyst at a mix ratio of 2%).... A mix ratio of 100:6 means 100 parts (by weight) of the Vac Cast resin should be mixed with 6 parts (by weight) of the Vac Cast hardener. Put simply, for every 100g of resin you need 6g of hardener. Say I need 1904 grams of resin, how much hardener would I use ?
If you had 1904g of resin then you know you need 6g of hardener for every 100g of resin so 1904/100=19.04; 19.04 x 6 = 114.24g of hardener (or just calculate 1904*0.06). I hope this helps and, once again, sorry I didn't get back to you right away. It would be great if I could always do this  Matt
Matt Statham
Easy Composites / Carbon Mods - Technical Sales
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TURK
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Group: Forum Members
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Visits: 662
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How do I make contact with the administrators of this site ......... the guys in the know ! as in Matt, as he did mention a few posts back that he could help me once I got to the molding stage. His Message box is full, and there seems to be no other way of contact ? This place is called 'Talk Composites' ......... but there doesn't seems to be an awful lot of talking going on !? Really stuck here guys, need help. TURK
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TURK
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Group: Forum Members
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Visits: 662
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Hi all, I really need an answer on this guys ........... will pattern coat primer stick to wood ? just waiting for an answer to begin mixing and pouring ! If I 'block-out' the underside of the resin mold with wood to save on resin, will I be able to remove the wood block once the resin has cured ? Also, the pattern-coat primer and hardener is a 100:6 mix ratio - what does that mean ? Say I need 1904 grams of resin, how much hardener would I use ?
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TURK
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Group: Forum Members
Posts: 101,
Visits: 662
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Hi folks, Matt - You did mention that when I got closer to creating my mold, to get touch. As an update to my quad headlight project, I thought I would post a few photos of how I'm getting on. And I still have an unanswered question from above. Does Vac-Cast Epoxy Resin stick to wood ? Now that all four parts of my headlight mounting brackets are ready ........ built with MDF, shaped with Polyester body filler and finished off with a couple of coats brushed-on 'Pattern-Coat Primer', I was ready to tackle the next phase of the operation. I've buffed the plugs up to a fine sheen but will also spray 'Ease Release 200' as a mold release agent prior to pouring the 'Vac-Cast' resin >>  I built a mold box giving me 18mm surrounding the plugs, which should in effect give me a female tooling plug with 18mm walls. Obviously, I won't be filling the mold box completely ......... just 15mm over the top of the plug should give me a good base >>  So far so good ......... I think !
I've read just about everything I could find concerning the use of 'Vac-Cast Epoxy Resin' ( which isn't much ), but I have seen an awful of how-to's on youtube concerning the use of RTV Silicon rubbers and various other cold casting techniques. So that's the method I'll be using.
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TURK
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Group: Forum Members
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Visits: 662
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Hi Matt, Many thanks for taking the time to respond and assist. Casting resins into moulds all seems very easy ....... actually it is ! As this is my very first attempt at this, and I usually research everything before hand, not knowing and not being accustomed to the materials you naturally don't know what works with what. The last thing you want is for a certain product reacting with another. I think this is where 'newbies' get confused or end up with a disaster on their hands, and not knowing what went wrong !
I'm fine with the polyester body filler, and brushing 'Pattern-Coat Primer' over the plugs. But then I have two choices ......... either I vacuum form directly over the top of those plugs, which will give me an slightly larger part than I need. But the intention would be to cast a polyester resin into that vacuum formed part. Polyester body filler and Pattern-Coat Primer which is a Polyester resin, makes sense.
Or, I could simply box out the plug and pour an RTV platinum silicon to create a mould, and then cast 'Vac-Cast' into the silicon resin mould. As nothing sticks to silicon ( apart from silicon itself ), demoulding should be straight forward.
Eventually what I want to end up with is, a backup of my plug ( or form ) so I can create more moulds from it in the future, as no mould lasts forever. Then it's to have a female mould made of 'Vac-Cast' resin and a male plug for vacuum forming my parts out of ABS plastic.
The issue is, 'Vac-Cast' resin is an 'Epoxy' resin ! how will that react with polyester body filler and if I use silicon to create a female mould, can I then cast the epoxy resin into it ? this is where I'm lost ........ can't find the information anywhere.
This is the finished plug at the moment, I've just got to sand down the radii a little more then I'm ready for casting. As you can see it's quite an intricate shape, but there no negative draft angles on it at all >>
Anybody had any experience doing this ?
The other thing you mention ........ 'blocking out'. I was intending to do that as I saw a tutorial on youtube where a guy was casting a urethane mould. Would I still be able to use wood as the 'block', and will I be able to remove the wooden block from my mould once it's cured, leaving me with sides to my plugs with 2cm walls and a hollow interior.
The release agent I use, I purchase from yourselves, it's the 'Easy-Lease' universal chemical release system. |
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Matt (Staff)
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Hi Turk,
When you get to the point where you're going to be casting the Vac Cast into your vac formed mould (i.e. to make a male former from Vac Cast) if you're at all unsure of the process then just let us know either through this forum or contact our support directly. Essentially, you're casting a two-part epoxy mix into your female mould which is a pretty straight-forward process.
The key is to reduce the amount of resin used by 'blocking out' the inside of your mould so that there is less capacity for the Vac-Cast; not only will this save you money on Vac Cast (and save you from producing a very heavy tool) but it will also reduce shrinkage and make it far easier to drill your vac pull-down holes (if you need them) because you'll be drilling through a thinner section.
Vac-Cast is a real staple of the vacuum forming industry because it is easy to use a reliable but, as I say, if you have any questions before use then just let us know.
Oh, final piece of advice - as always - test your release of the Vac Cast from your vac forming using your chosen release agent in a small area first. Make sure you get a good release with the combination of materials you're using before comitting to the whole job.
I look forward to seeing how you go.
All the best, Matt
Matt Statham
Easy Composites / Carbon Mods - Technical Sales
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TURK
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Group: Forum Members
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Visits: 662
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Very talented man Matthieu. Really enjoying all your videos, it's nice to see people taking the time to educate others. I can't wait to see the 'Vac-Cast' tutorial, I would of worked out the correct procedure by then hopefully. If I knew more about the subject, I would be the first to make a tutorial on making plugs and moulds. My research shows that there are so many ways of accomplishing plug and mould fabrication. I guess when it comes down to it, you have to continually test and get accustomed to a technique that works best for you. There are so many different products out there to chose from, I'm just getting so tired of all those youtube videos that show people casting things like pen blanks, earrings, jewellery or toy soldiers ......... most times without any instruction of what is happening what they're using, and a way too loud sound track that is either heavy metal or a bad 70's p0rn film ! Once in a while I would like to see a true pro at work explaining what's he's doing. When the time comes, I'll be posting how-to videos on plug and mould design and vacuum forming, as there's not a lot out there. At the moment I'm making some plugs made of MDF, covered and shaped with easy sand Polyester body filler >>  I'm just fine tuning them now, so a bit more sanding and they'll be the exact same size as the original part I need. They're not copied from anything, it's a design from scratch so no template. The next phase will be to brush a couple of layers of 'Pattern-Coat Primer' to give them that eggshell like finish. I then have two choices, I can vacuum form directly that shape using 2mm ABS, and pour a mix of 'Vac-Cast' Epoxy resin into the vac formed part and end up with a solid male plug, or I can make a box mould and pour 'Vac-Cast' Epoxy resin into a box mould and end up with a female mould. Ideally, I would like to test both versions and see how the ABS plastic performs. Both female mould and a male mould have to be hard wearing and heat resistant as it's for vacuum forming. I'm hoping I can workout the correct procedure for this, as I'll be using this technique for the headlight covers also. Here's an example of some headlight covers I made last year, using a DIY vacuum forming machine that I built. They were OK, but no where near strong enough. I concluded that the covers should be at the very least 2mm in thickness, but as I want to build a quality product I'm going to use 3mm ABS. >>  The aluminium headlight bracket you see in the picture, was one of my very first prototypes, while being a little on the flimsy side it allow me to workout the correct positioning of the headlight units. So the plugs I'm currently working on, are in fact a plastic version of the template you see there. But the headlight units will be installed inside the brackets and not in front as in the picture. >>  I'm also working on the clear cover version of the quad headlights also >>  Any help on the project will be greatly appreciated Matthieu, even criticism ........ would you have done it completely differently !? TURK
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