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Since these pictures were taken I have filed away on either side where the clip-ons go to fit the LED indicator strips vertically and underneath the headlamp location have filed a flat for an LED running light. It is now about a day away from being ready for primer resin.
I have learned quite a bit about mold making in these last few months
1. Whenever you manufacture a mold just as you think it is finished you realise that there is some (essential) modification that would make it better or you find a parameter that you hadn’t considered so it has to change, so pondering before manufacturing is not wasted time.
2. Make your skeleton about 5mm smaller in very dimension than the expected finished product.
3. Make the skeleton accurately, the human eye can spot amazingly small deviations in the radius of a curve or flat spots on a double curvature.
4. Ply wood is about the worst material for the skeleton because when you break through it is difficult to shape edge on. I used ply because I had loads of offcuts cluttering up my garage. MDF would be better and others have suggested balsa wood but I have no idea where to obtain any locally.
5. Male molds are a lot simpler to make than female molds and a lot easier to rub down but require a lot of “reverse” thinking. Obviously there will be a “smooth” side to the finished article and the choice is sometimes made for you depending on what is on display when on the bike.
6. When designing the mold do so bearing in mind the ability to form in one piece so you do not have to go to the complication of split molds, not always possible for example with the tank. Female molds must have tapering non – parallel sides to enclosures otherwise the finished article will not release from the mold.
7. Consider carefully the mounting arrangements of the finished article in the design of the mold – something I have absolutely failed to do and will probably suffer from later.
8. Use only one grade of foam as a filler between the skeleton, differential rubbing down capability leads to more filling downstream.
9. Buy filler in big tubs and wet and dry in bulk off the internet– it is lot cheaper that way.
10. The grades of wet and dry you buy in bulk will not accord with what you actually need to do the job. 180 and 240 grade gets far more use than 600 800 and 1000 grade.
11. Resign yourself to accepting that whenever you mix filler you will always have precisely either 95% or 130% of the filler you need to complete the task.
12. Also accept that you will discover the most difficult place to fill when the mixed-up filler has less than 20 seconds workable life.
13. It always rains on days when you have rub down so you have to stay in the garage and all the dust goes everywhere.
14. When rubbing down, never attempt to rub out pin holes, you will either break through or spend a lot of time taking the depth of the pin hole out over quite a large area. Filling and rubbing down the pin holes takes virtually no time, filling and rubbing down a breakthrough can take hours
15. The moment you feel the filler starting to coagulate throw the mix away.
16. Accept that the most difficult place to fill and to rub down will be the most “in your face” part of the finished product.
17. Every job, making the skeleton, filling the skeleton with foam, skimming with filler takes approximately 2 x the time you think it will. Rubbing down and completing the mold take 3 x the time you hope it will.
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