Always Overdo it With the Glue

[lakeroadster]

Thanks! Do you think these would work with 30 minute epoxy?

I'm going to guess no. I tried it with JB Weld, and it was too thick.

 

[DaHabes]

Follow the instructions in the PDF for great fillets. This was captured from a thread somewhere here on TRF. You don't need carbon paper. Just crease a clean sheet of paper and run a pencil lead sideways on each side of the crease, apply the lead side to the fin joint and score with the tool you are going to use to make the fillets.

Use these to make the fillets > https://smile.amazon.com/AmyTalk-Baking-Fondant-Stainless-Flower/dp/B01DPBNSD6/ref=sxin_24_pa_sp_search_thematic_sspa?crid=3NO3TKAJBLQP7&cv_ct_cx=fondant+tools&keywords=fondant+tools&pd_rd_i=B01DPBNSD6&pd_rd_r=724b3dd8-2465-4427-8853-966b23650953&pd_rd_w=tS0N8&pd_rd_wg=Buli1&pf_rd_p=9dca4024-3e25-44da-8740-13759fcb9369&pf_rd_r=DJ6WZENRXB3453QW2B2Z&qid=1652411171&sprefix=fonda,aps,120&sr=1-4-a73d1c8c-2fd2-4f19-aa41-2df022bcb241-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzVEY4WFZJSEE0MDIwJmVuY3J5cHRlZElkPUEwNDI1MzE0M1RROVRFUFQwTFRZMCZlbmNyeXB0ZWRBZElkPUEwNDQ2NTYzM01PM0g0SFgwOEtLSyZ3aWRnZXROYW1lPXNwX3NlYXJjaF90aGVtYXRpYyZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

Rule of thumb is to make the fillet radius 4-8% of the fin root chord. Calculate the radius, select the right tool. Dip in isopropyl alcohol and shake off the excess before you draw the fillet. Clean off the tool with alcohol and a paper towel.

Done carefully you can get perfect fillets every time the first time (with a bit of practice).

 

[waltr]

And a good video on the fillet process:
https://www.mach1rocketry.com/badass-videos?pgid=k8hglni52-b44cd7c0-0294-4757-bbd5-41b11c028956
One additional step I found to do is:
After pulling the tape, wet your gloved finger with alcohol and run along the edges of where the epoxy meets the BT and Fin. This blends the epoxy edge, may have a edge due to thickness of the masking tape, and eliminates sanding later.

 

[PatD]

I use the fondant tools and color them with a black sharpie. Use that to draw the lines and wipe it off the tool with alcohol when done. Works for me.

 

[AfterBurners]

It’s the epoxy I overdo it with. Super strong but ugly when I use too much.
Like this:

View attachment 495981

its not bad just wipe off the excess and form a fin fillet.

 

[brockrwood]

I use the fondant tools and color them with a black sharpie. Use that to draw the lines and wipe it off the tool with alcohol when done. Works for me.

Fondant? What be these useful fondant tools of which you speak?

 

[Spitfire222]

Fondant? What be these useful fondant tools of which you speak?

Fondant Tools

 

[brockrwood]

Fondant Tools

Ah! Thanks!

 

[Lee]

They work great. Yes, I use carbon paper to mark tape lines. I lay down a bead of Quick & Thick. Let dry, then add a layer of Bondo which is sandable. Consistent results every time.