How would you mold this...?

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How would you mold this...?

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BlackNDecker	BlackNDecker posted 11 Years Ago HOT Topic Details
Group: Forum Members Posts: 92, Visits: 251	In an attempt to refine my technique, I am going to scale back and try a smaller project. This is a solid plug that will eventually become the lower plenum of my intake manifold. I made it by making a mold of the aluminum flange and building a foam core. I added tubular elbow and a throttle body mounting plate. The whole thing has been sprayed with primer and sanded smooth. It's not glass smooth but pretty smooth nonetheless. Here are some pics. This intake manifold is a multipiece design...the lower section I've made will replace this section: Not perfect...but I can't tell you how elated I was to actually make a successful mold!!! Fast forward...this is what it looks like and how it will mount to my intake manifold: Is it even possible to mold this? There are some really tight crevices that worry me. I am also unsure about molding the cylindrical tube.
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BlackNDecker	BlackNDecker posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 92, Visits: 251	I won't be able to mold this as a one piece unit. The shape is too complex. It will have to be two separate pieces that are then bonded together. <-- This is what I am most nervous about. I don't know how to prepare the bonding seams on the two halves of the final part....and, Easycomposites won't post the 3rd and final video in their series on complex multi-part molds which shows how to do it(((
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Hanaldo	Hanaldo posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	BlackNDecker (19/06/2014) I won't be able to mold this as a one piece unit. The shape is too complex. It will have to be two separate pieces that are then bonded together. <-- This is what I am most nervous about. I don't know how to prepare the bonding seams on the two halves of the final part....and, Easycomposites won't post the 3rd and final video in their series on complex multi-part molds which shows how to do it((( I don't believe that video would answer your question anyway, as EC have built that mould to use pre-preg and build the part in one piece then disassemble the mould after it is cured. No bonding together in that one. With the shape of your part I believe you could do the same, but the techniques for doing it with infusion are slightly tricky and will take some practice. Definitely a good idea though, as doing it in one piece will always be be stronger. For bonding together the two halves, the way I do it is to place some individually cut out cells of soric along the bond line in the layout, which increases the bonding area. But given your part deals with air flow, I suggest doing it a different way. See my thread about trimming the parts down. Using a cutter and blocking it down will be difficult to get a nice bond line, believe me I've tried. Make the excess flange material your friend and use it as a guide. Then for bonding, give each edge a quick rub up with 60 grit and wipe them with acetone. Then what I do is place polyethylene packaging tape on the outside surface of the part approx 1mm below the edge. Do this for each edge to be bonded, and go slowly to line it up nicely. Then use a thixotropic structural adhesive and apply it to each edge. Then for parts that are a bit difficult to hold, place one half loosely back in its mould to hold it, and then join the two pieces. Take your time to make sure everything is lined up nicely, if you use a good adhesive with a high tack then this shouldn't be too difficult. Use a popstick to smooth out the adhesive that squeezes out the sides, this is why you have the packaging tape. Once you have it lined up the way you you want it, leave it for a bit to cure. Don't let it cure fully though, you are looking for the stage where the adhesive is still soft but is tacky enough that the pieces will be held pretty firmly (for me it's about an hour). Then gently pull off the packaging tape, leaving you with a nice sharp bond line. Once it has cured fully, place some 2" wide strips of carbon fibre or fibreglass along the bond line on the inside and wet them out with a paint brush. I then use an orbital sander to smooth out the bond line on the outside, but this is optional as the tape will give you a pretty neat line.
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