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Pkzipper
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Group: Forum Members
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Hello all, Here is a post ( http://www.talkcomposites.com/23154/CF-clips-for-car-dashboard) that covers one part of my question that i do not think has been really answered and i would love some more clarity on this. I have a few ideas like making partial backing molds to be glued or templates to align the posts and clips. Easy in principle but strength is vital as shown in the picture of the post showing gussets. The part of this questions is the texture on the original part and how to remove it effectively. Obviously smoothing the original is an option but that would meaning destroying it. Also the original is plastic and smoothing it is very difficult and time consuming. I also have thought about making a mold of the original, then making copy of the panel, from FG, from the mould and smoothing and adjusting it to my liking. It seems like that there might be a lot of un-necessary effort and steps in this approach. Finally, I though about just adding an extra layer, or two, of gel coat when making the mold so that I can just sand and polish the mold for the finished product. I would love to eliminate the trail and error and get some practical advice from experience.
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Hanaldo
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Group: Forum Members
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Honestly, I know it seems like much more work and a bit of a waste, but in my opinion when you can't modify the original then making a splash mould and a new pattern is the best way to go about getting the surface finish that you are after. It is so much quicker and easier to work on the male pattern than it is to work on the female mould. Tooling gelcoat is beautiful stuff to polish up, but trying to sand out texture is a nightmare and you end up just going with 'good enough' rather than what you actually wanted. When you can just quickly flat down the texture with some 180 grit, hit it with primer filler, and then move on to finishing it to the standard you wanted. Then your mould comes off the pattern perfectly and you can just get straight into using it without running into potential dramas like sanding into porosity etc. All in all, on stuff the size of a vehicle interior panel it costs you maybe $30 in materials and a day of labour. For me that makes more sense than half a day of trying to refinish your mould and coming away with a mould that isn't really what you wanted.
As for the clips and fasteners, well... There's a reason I don't really do interior parts. There isn't really a perfect solution for this, and it comes down to you finding the solution that works for the job you're doing. For the most part, that means bonding on things like rivnuts, bighead fasteners, nutplates, threaded rod etc. Obviously a jig helps here, whether that's one you make yourself or whether you use the original mounting location and find a way to hold the part in place while the adhesive cures.
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Pkzipper
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Group: Forum Members
Posts: 7,
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+xHonestly, I know it seems like much more work and a bit of a waste, but in my opinion when you can't modify the original then making a splash mould and a new pattern is the best way to go about getting the surface finish that you are after. It is so much quicker and easier to work on the male pattern than it is to work on the female mould. Tooling gelcoat is beautiful stuff to polish up, but trying to sand out texture is a nightmare and you end up just going with 'good enough' rather than what you actually wanted. When you can just quickly flat down the texture with some 180 grit, hit it with primer filler, and then move on to finishing it to the standard you wanted. Then your mould comes off the pattern perfectly and you can just get straight into using it without running into potential dramas like sanding into porosity etc. All in all, on stuff the size of a vehicle interior panel it costs you maybe $30 in materials and a day of labour. For me that makes more sense than half a day of trying to refinish your mould and coming away with a mould that isn't really what you wanted. As for the clips and fasteners, well... There's a reason I don't really do interior parts. There isn't really a perfect solution for this, and it comes down to you finding the solution that works for the job you're doing. For the most part, that means bonding on things like rivnuts, bighead fasteners, nutplates, threaded rod etc. Obviously a jig helps here, whether that's one you make yourself or whether you use the original mounting location and find a way to hold the part in place while the adhesive cures. Thank you so much for the direct response. I figured as much that it would be easier to make a new pattern and what I was looking for was the answer about the female mold. I am curious about the term "Splash Mold"? Not an expert and not really sure what the exact definition to it is?
As for the clips I do hope someone can chime in. Getting them on i am sure i can figure out with a simple mold made from that side with keys of sorts to marry up with the face half. That side is not visible so making it look pretty means nothing it is just strength. They are thin pins, vertical flat fins and pyramid shape guides that would be stronger then heck in carbon but snap off quickly in plastic. I was even thinking a silicone mold to make the parts and then gluing it on?
Hope some one can shed some experiance to this.
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Hanaldo
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Group: Forum Members
Posts: 2.5K,
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Splash mould is just a quick mould that's a bit flimsier and made with cheaper materials and quickly made, figuratively 'splashing' fiberglass and resin onto the job. You can really just use regular gelcoat and general purpose polyester resin. It only needs to last one pull, so it doesn't need to be as strong as a proper mould. The important thing is to not make it so flimsy that it can warp easily and leave you with bad fitment we you make your proper mould/part.
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Pkzipper
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Group: Forum Members
Posts: 7,
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+xSplash mould is just a quick mould that's a bit flimsier and made with cheaper materials and quickly made, figuratively 'splashing' fiberglass and resin onto the job. You can really just use regular gelcoat and general purpose polyester resin. It only needs to last one pull, so it doesn't need to be as strong as a proper mould. The important thing is to not make it so flimsy that it can warp easily and leave you with bad fitment we you make your proper mould/part. Ah yes thank you, that is what I thought.
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Furrari
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Group: Awaiting Activation
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+x+xSplash mould is just a quick mould that's a bit flimsier and made with cheaper materials and quickly made, figuratively 'splashing' fiberglass and resin onto the job. You can really just use regular gelcoat and general purpose polyester resin. It only needs to last one pull, so it doesn't need to be as strong as a proper mould. The important thing is to not make it so flimsy that it can warp easily and leave you with bad fitment we you make your proper mould/part. Ah yes thank you, that is what I thought.
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Furrari
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Group: Awaiting Activation
Posts: 63,
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Hi. Don’t know if it’s relevant but I am currently doing an envelope bagging of the lock cover plate for my kit car ( waiting for the base coat to go tacky as I type this). The fixingings on this are just holes that a screw and cover go into. I’ve taped bits of stirring stick onto the back and filled the hole with mould wax so there should be no leakage and should be easy to remove from the back later.
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Matt (Staff)
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Group: Forum Members
Posts: 680,
Visits: 1.9K
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+xHi. Don’t know if it’s relevant but I am currently doing an envelope bagging of the lock cover plate for my kit car ( waiting for the base coat to go tacky as I type this). The fixingings on this are just holes that a screw and cover go into. I’ve taped bits of stirring stick onto the back and filled the hole with mould wax so there should be no leakage and should be easy to remove from the back later. Hi, We've not been online over the weekend but basically Hanaldo has stated what would be the EC opinion anyway. It sounds like you're aware of the choices you have (in removing the texture from your original parts) which are to: 1. Sacrifice the original (by filling and smoothing out the texture).
This is quickest and most accurate (least distortion). Disadvantage of course is that it sacrifices the original. 2. Do a very thick gelcoat on the mould and then smooth out the texture in the mould.
This can offer a decent compromise allowing you to not sacrifice the original but to reduce the workload and cost and reduce the risk of distortion however flatting and polishing 'in the negative' is much more difficult, it's hard to see when you've got it right and you're often flatting on the inside of a concave plain which is much more difficult. Also, although you reduce the risk of distortion from going back and forth between part and mould you will introduce some inaccuracy by necessarily flatting down to the lowest point in the texture rather than being able to build up to the highest point or striking a mid point (as you would with options 1 or 3. 3. Take a quick (splash) mould off the original and then make a GRP copy of the original (a splash part) which you can modify, including taking any texture out.
This gives you the most scope for 'correction' and avoids sacrificing the original. Disadvantages are that it's the most work, the most cost (in materials) and can introduce distortion because you're turning the whole process through twice by the time you get to the finished part. Moulding can be a bit like 'Chinese Whispers' and some distortion can creep in if you're not careful. There's pros and cons to all approaches; choosing the right one is subjective and depends on your priorities.
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Pkzipper
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Group: Forum Members
Posts: 7,
Visits: 21
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+x+xHi. Don’t know if it’s relevant but I am currently doing an envelope bagging of the lock cover plate for my kit car ( waiting for the base coat to go tacky as I type this). The fixingings on this are just holes that a screw and cover go into. I’ve taped bits of stirring stick onto the back and filled the hole with mould wax so there should be no leakage and should be easy to remove from the back later. Hi, We've not been online over the weekend but basically Hanaldo has stated what would be the EC opinion anyway. It sounds like you're aware of the choices you have (in removing the texture from your original parts) which are to: 1. Sacrifice the original (by filling and smoothing out the texture).
This is quickest and most accurate (least distortion). Disadvantage of course is that it sacrifices the original. 2. Do a very thick gelcoat on the mould and then smooth out the texture in the mould.
This can offer a decent compromise allowing you to not sacrifice the original but to reduce the workload and cost and reduce the risk of distortion however flatting and polishing 'in the negative' is much more difficult, it's hard to see when you've got it right and you're often flatting on the inside of a concave plain which is much more difficult. Also, although you reduce the risk of distortion from going back and forth between part and mould you will introduce some inaccuracy by necessarily flatting down to the lowest point in the texture rather than being able to build up to the highest point or striking a mid point (as you would with options 1 or 3. 3. Take a quick (splash) mould off the original and then make a GRP copy of the original (a splash part) which you can modify, including taking any texture out.
This gives you the most scope for 'correction' and avoids sacrificing the original. Disadvantages are that it's the most work, the most cost (in materials) and can introduce distortion because you're turning the whole process through twice by the time you get to the finished part. Moulding can be a bit like 'Chinese Whispers' and some distortion can creep in if you're not careful. There's pros and cons to all approaches; choosing the right one is subjective and depends on your priorities. Hello and thank you Matt, Option one is the one I need to be prepared for as some of the original components have high value. I am left with the choice of two and three. I appreciate you cannot pass on definitive direction as there is not one right way nor do you want the blow back if it fails. I am leaning towards option three as from what I am hearing sanding a positive is way easier than sanding a negative mold. Also, sanding and polishing pattern coat primer and high gloss is way easier than gel coat! Its just the flex and distortion issue. A well made mold should eliminate the possibility of distorting the part but the finish would be suspect. The splash mold is my concern and I know it is my choice but I am just looking for reference. Splash mold's, as supposed to permanent molds, make a quick replica of the original but that original could be effect if the mold is too flimsy but how do you gauge that? Or do you build a stronger mold from glass to be safe but at what cost? What about cost effective backing media like Plaster or something that is cheap and rigid? I would think it might be better in the case of making a working replica to focus on strengthening it for it not to warp while its being worked but with what? Plaster is heavy but does not expand. Silicone is too flimsy and expanding foam well is expanding and could/would it distort the form while expanding. Am I over thinkin this?? Finally can you chime in on the issue of the posts, clips and attachment points on the back? Thank you again P.S Where are all the PDF from the resource section? I only see the videos. I want to look at the PDF that had reference to using honeycomb.
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Matt (Staff)
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Group: Forum Members
Posts: 680,
Visits: 1.9K
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+x+x+xHi. Don’t know if it’s relevant but I am currently doing an envelope bagging of the lock cover plate for my kit car ( waiting for the base coat to go tacky as I type this). The fixingings on this are just holes that a screw and cover go into. I’ve taped bits of stirring stick onto the back and filled the hole with mould wax so there should be no leakage and should be easy to remove from the back later. Hi, We've not been online over the weekend but basically Hanaldo has stated what would be the EC opinion anyway. It sounds like you're aware of the choices you have (in removing the texture from your original parts) which are to: 1. Sacrifice the original (by filling and smoothing out the texture).
This is quickest and most accurate (least distortion). Disadvantage of course is that it sacrifices the original. 2. Do a very thick gelcoat on the mould and then smooth out the texture in the mould.
This can offer a decent compromise allowing you to not sacrifice the original but to reduce the workload and cost and reduce the risk of distortion however flatting and polishing 'in the negative' is much more difficult, it's hard to see when you've got it right and you're often flatting on the inside of a concave plain which is much more difficult. Also, although you reduce the risk of distortion from going back and forth between part and mould you will introduce some inaccuracy by necessarily flatting down to the lowest point in the texture rather than being able to build up to the highest point or striking a mid point (as you would with options 1 or 3. 3. Take a quick (splash) mould off the original and then make a GRP copy of the original (a splash part) which you can modify, including taking any texture out.
This gives you the most scope for 'correction' and avoids sacrificing the original. Disadvantages are that it's the most work, the most cost (in materials) and can introduce distortion because you're turning the whole process through twice by the time you get to the finished part. Moulding can be a bit like 'Chinese Whispers' and some distortion can creep in if you're not careful. There's pros and cons to all approaches; choosing the right one is subjective and depends on your priorities. Hello and thank you Matt, Option one is the one I need to be prepared for as some of the original components have high value. I am left with the choice of two and three. I appreciate you cannot pass on definitive direction as there is not one right way nor do you want the blow back if it fails. I am leaning towards option three as from what I am hearing sanding a positive is way easier than sanding a negative mold. Also, sanding and polishing pattern coat primer and high gloss is way easier than gel coat! Its just the flex and distortion issue. A well made mold should eliminate the possibility of distorting the part but the finish would be suspect. The splash mold is my concern and I know it is my choice but I am just looking for reference. Splash mold's, as supposed to permanent molds, make a quick replica of the original but that original could be effect if the mold is too flimsy but how do you gauge that? Or do you build a stronger mold from glass to be safe but at what cost? What about cost effective backing media like Plaster or something that is cheap and rigid? I would think it might be better in the case of making a working replica to focus on strengthening it for it not to warp while its being worked but with what? Plaster is heavy but does not expand. Silicone is too flimsy and expanding foam well is expanding and could/would it distort the form while expanding. Am I over thinkin this?? Finally can you chime in on the issue of the posts, clips and attachment points on the back? Thank you again P.S Where are all the PDF from the resource section? I only see the videos. I want to look at the PDF that had reference to using honeycomb. >> Am I over thinkin this?? Yes, definitely! Forget using weird and wonderful alternatives to GRP; plasters, silicones - they're not the way to do this. It sounds like you just need some experience with GRP; conventional polyester gelcoat, chopped strand matt and polyester resin layup. Distortion is caused by shrinkage, a good laminator knows to take their time, building up layers one at a time over a period of a few days, this will eliminate most shrinkage issues. The thickness of the splash moulds and splash parts will tend to determine themselves; you just need them to be stable and secure without using unnecessary material making either of them too sturdy. Start simple, take a splash mould, satisfy yourself up to that stage. Then make the splash part (with a thick gel so you can modify the texture) and then make your final mould. You'll be a dab-hand by then. Use Uni-Mould when you make the final mould; it will be much thicker and will need a vinylester gelcoat so Uni-Mould is definitely the way to go. >> P.S Where are all the PDF from the resource section? At the moment we just have the videos. We did have some PDFs (not related to honeycomb) but we're gradually updating a lot of this content. I'm afraid we don't currently have any tutorials or guides that relates to working with honeycomb although this is something that we plan to do fairly soon. >> Finally can you chime in on the issue of the posts, clips and attachment points on the back? Did you attach the image, I can't see it? There have been lots of discussions about mounting clips, I'm not 100% sure what your particular requirement is but if you can't find your answer already then please let me know some more about what you're trying to do.
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