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<\/a>The Epoxy<\/h2>\n
I wanted a proper peanut epoxy mix – no drooping at all, no dripping. So I went for the 105\/206\/403 mixture.<\/p>\n
I mixed 15\/3 of 105\/206. This did two 15cm lengths with a little bit left over. With 6 fins (both sides) we have 204cm of fillets. So we will need about 7 times this quantity of epoxy. i.e. 105\/21. Though we are very likely to do this in 6 (possibly 3 if we are feeling extra confident) jobs.<\/p>\n
I was careful not to introduce any air while mixing and I carefully filtered the 403 twice to ensure that I didn’t have any clumps. I had about 10 mins of 20 mins time left to apply the epoxy to the filleting area and create the required profile.<\/p>\n
Delivery of Epoxy to Join<\/h3>\n
I don’t need to pass this epoxy through any tube (like before), just from a syringe. \u00a0I just packed it in and then squeezed it into the spot. I made sure that I was putting in enough epoxy along the fillet join.<\/p>\n <\/p>\n After it had dried, I did the sanding using a specially made sanding stick. I made the sanding stick by Gluing Grit 60 Sandpaper to one end and Grit 240 at the other end. I used Selleys Glue to attach the sandpaper. It had to dry overnight. (Yes, lots of waiting).<\/p>\n Here are two pictures that compare one side (sanded) with the other side (un-sanded)<\/p>\n The finish is excellent – very smooth. There is still a line where the masking tape was. This line needs to be removed by using filler to bring it to the fibrerglass air-frame.<\/p>\n As a reminder, this effort is being made because we want to reduce Interference drag which can have a significant impact on a rocket’s performance.<\/p>\n My neighbor suggested the filler as a technique for removing the line. He had a go on this test fillet I did. I took some pictures of what he did. (Of course I’ll be doing this myself when it comes to the real thing).<\/p>\n Good aye? Can you tell where the fillet starts\/ends?<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" Practice makes Perfect I wanted to practice the external fillets again.\u00a0I have only one chance at this , so the procedure needs to be clear in my mind. My Test bed I nailed two pieces of wood. Then I used a 10mm aluminium rod to accurately measure 10mm lines on each edge. Then I taped … Continue reading External Fillets – Second Trial<\/span> <\/a><\/a><\/a><\/a>Sanding<\/h3>\n
<\/a><\/p>\n<\/a>The (almost) Final Product<\/h3>\n
<\/a><\/a>Removing the line<\/h3>\n
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