Announcement

Collapse
No announcement yet.

Fabricating Cupholders 2

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Fabricating Cupholders 2

    I don't know if I keep on going with my other thread if anyone will see this (maybe someone could let me know) so I'm starting a new one.

    Well, I tried a few different things to mold the cupholders in my expedition to create new ones in my Montero.

    I looked into RTV silicone but couldn't find any readily available. I went to a hobby shop to look for it and they didn't have any but they did have some latex rubber that's used for taking impressions of objects to make molds and then make new rocks, etc for train sets so I tried that.

    It made a beatiful impression of the cupholders and released well but it was flimsy so before I took it out, I filled it with some "Great Stuff" expanding foam which worked really well. It dried and I had a good solid yet slightly flexible mold to use.

    The problem happened when I put the fiberglass on to make my new cupholder. At first, I put one coat of resin on and let it sit for a few minutes before I decided that I would probably have to go ahead and use fiberglass cloth(didn't have any) instead of putting plain resin on the mold so I wiped it off before it dried.

    This morning (got some cloth) I went out to try again with the cloth and resin and noticed that my mold was severely warped. The only thing I can figure is that maybe the resin reacted with the rubber?

    Does anyone have any ideas as to how I can remedy this?

    Someone in another thread suggested using fiberglass to make the impression and then fiberglass to mold the new cupholder(or whatever part). It seems to me that the only way to do this would be to apply some kind of separator between the fiberglass mold and the new layer of fiberglass or surely they would stick together.

    Ideas on this?

    Thanks.

  • #2
    Tape!

    Comment


    • #3
      I made my cupholders out of 1/2" MDF. I used a router and cut a hole in several sheets and stacked them. I even made the bottom one a little smaller and rounded over the transitions. Sanded the whole thing smooth with my dremel and then sprayed the whole thing with the spray-in bedliner stuff from Wal-Mart. Two cans, thick coverage. It's waterproof, and has a unique texture that doesn't show scratches...
      JoshB [BadPakt]
      TruckPC [||||||||||] 90% (Tweaking Software)
      FrodoPlayer / Lilliput / Opus 150 / AMD Sempron / PowerMate
      Roady2 ((XM)) / Sony W600 / Bluetooth / Ford Ranger EDGE

      Comment


      • #4
        Originally posted by Shadow View Post
        Tape!
        dont forget the tin foil

        Comment


        • #5
          Fiberglass Matt doesn't use tinfoil, why should this guy?

          Comment


          • #6
            Originally posted by BadPakt View Post
            I made my cupholders out of 1/2" MDF. I used a router and cut a hole in several sheets and stacked them. I even made the bottom one a little smaller and rounded over the transitions. Sanded the whole thing smooth with my dremel and then sprayed the whole thing with the spray-in bedliner stuff from Wal-Mart. Two cans, thick coverage. It's waterproof, and has a unique texture that doesn't show scratches...

            That's interesting. Do you have pictures?

            Comment


            • #7
              Originally posted by FC3S View Post
              dont forget the tin foil

              Are you saying put the tin foil over my mold to prevent sticking, etc.?

              Comment


              • #8
                here's what i think the problem is... great stuff continues to expand and move even after you think it's done. Latex is pretty benign stuff so i don't think it reacted at all with the resin. What is more likely is that the great stuff continued to expand and shift beneath the latex and that's what warped your mold.

                Try again with the latex, but fill it with something that's not liable to shrink, move or expand during cure.

                Here's a thought: make your impressions with the latex, then lay fiberglass and resin inside that until it's nice and sturdy... then pop the latex/fiberglass part out of the cupholder.

                Then the latex is not only your "separator" but it captures surface detail very well which will transfer to your new cupholders if you use a gelcoat.
                Et ipsa scientia potestas est.

                Worklog for my 2007 Civic Si ...f*** it...
                Pictures of the Corolla (retired)here
                Need to make something? Here are a few ideas.

                Comment


                • #9
                  Originally posted by GoHybrid View Post
                  here's what i think the problem is... great stuff continues to expand and move even after you think it's done. Latex is pretty benign stuff so i don't think it reacted at all with the resin. What is more likely is that the great stuff continued to expand and shift beneath the latex and that's what warped your mold.

                  Try again with the latex, but fill it with something that's not liable to shrink, move or expand during cure.

                  Here's a thought: make your impressions with the latex, then lay fiberglass and resin inside that until it's nice and sturdy... then pop the latex/fiberglass part out of the cupholder.

                  Then the latex is not only your "separator" but it captures surface detail very well which will transfer to your new cupholders if you use a gelcoat.

                  Good Idea. So would I put the gelcoat on the mold first? Can you explain? I've never done a gelcoat. Is it a different material from the resin?

                  Comment


                  • #10
                    Here's a good way to understand gelcoat. Fiberglass (cloth and mat) is a solid, so it wants to hold it's own shape, and resin is a liquid, so it will form around the solids. So you can imagine what this looks like when it dries. You've got a hard fiberglass part, but the texture feels like fiberglass because that's what sticks out through the resin.

                    Gelcoat is just regular resin with one important difference: its cure is air-inhibited. That means that any gelcoat exposed to the air is not going to cure. That means that the gelcoat below the exposed surface WILL cure.

                    What does that mean? It means gelcoat gives you a chance to use a liquid to exclusively capture any surface details from the impression of your original part without interference from the reinforcing fabric. That it remains tacky on the outside post-curing means that you can still reinforce it and get a good chemical bond. The difference is now there's a solid layer that makes up the surface of your new part that the reinforcing fiberglass can't get through.

                    let me see if i can explain it better in terms of layers from bottom to top...

                    Step 1 (making the pattern): Original Cupholder--->Latex--->Reinforcement (try alumilite)

                    Step 2: separate the pattern from the Original Cupholder.

                    Step 3 (replicating the original): Spray or Brush Gel-Coat--->(wait for gelcoat to cure)...then--->Standard fiberglass+resin.

                    Step 4: trim and separate new part from pattern.

                    Hope that helps. There's lots of great info on gel coats through Google too.
                    Et ipsa scientia potestas est.

                    Worklog for my 2007 Civic Si ...f*** it...
                    Pictures of the Corolla (retired)here
                    Need to make something? Here are a few ideas.

                    Comment


                    • #11
                      I thought about what I would use for cupholders quite extensively and saw some 3" pipe couplers in the hardware store and settled for those. You can see my project under the worklogs section titled "2003 Dodge Dakota" for a few examples.
                      Check out the updates. Project 2003 Dakota worklog: http://www.mp3car.com/vbulletin/showthread.php?t=85490


                      IS JACK BAUER GONNA HAVE TO SMACK A *****?

                      Comment


                      • #12
                        Originally posted by Shadow View Post
                        Fiberglass Matt doesn't use tinfoil, why should this guy?
                        rofl

                        fibreglass Matt is a pro



                        and yes, tape/tinfoil prevents sticking, dont really NEED the tinfoil, as a lot of people dont use it, but i like to, im not really sure why

                        Comment


                        • #13
                          extra saftey thats why. If resin gets on ANYTHING it's stuck there, once it dries it's not comming off...look at my garage floor if you don't believe me. I use tin foil or even glad press and seal to get the first layer down.

                          -Mike

                          Comment


                          • #14
                            cupholders? I just took an old dixie cup dispenser and sliced it at an angle. Then I just bondo'd it into a fresh cut hole in front of my armrest. It is the _perfect size_ to hold cans.

                            Comment


                            • #15
                              i woulda left it dispensing dixie cups!... then all i'd need is a faucet... hmm...
                              Et ipsa scientia potestas est.

                              Worklog for my 2007 Civic Si ...f*** it...
                              Pictures of the Corolla (retired)here
                              Need to make something? Here are a few ideas.

                              Comment

                              Working...
                              X