Nosecone Help

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sheena

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First, ,thanks for all the help with the body tubes I'm pretty sure they came out ok.My plastic nosecone has a line of raised plastic on one side and a groove directly opposite of it on the other side (mold lines ?). I'm guessing just sanding off the high side will work but what does a person use to fill in the groove on the other side with? Thanks ,and if I'm forgetting anything please let me know. :)
 
I general use 'Bondo spot & glazing putty', other folks will (no doubt) sing praises for 'squadron putty'. pretty sure they both work. glazing putty shrinks as it dries so you need to use a bit more than one might think, since you're working on a plastic cone you can wet sand the excess with 320 grit w/o clogging up the paper (balsa requires a few more steps) HTH
Rex
edit
spot and glazing putty can be found in the automotive section, note you do Not want the 2 part auto body putty.
 
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I generally use an exacto knife to shave off the plastic on the high side. Then sand with 220 or 400 grit.
 
If the NC is really bad, the manufacturer *MIGHT* replace it if you try contacting them. Estes has been known to do this.
 
Thanks folks,I've already got that Bondo putty so I'll use that. The nosecone really isn't that bad but this is the first rocket I'm building just for myself and I'm being extra fussy.
 
Thanks folks,I've already got that Bondo putty so I'll use that. The nosecone really isn't that bad but this is the first rocket I'm building just for myself and I'm being extra fussy.


Bondo Spot Putty is meant to be used over primer so apply after your primer coat of paint. The putty is actually thick primer and that's why it's applied after the primer. Squadron putty is meant to stick to the raw plastic. That's the difference between the two ;)
 
Bondo Spot Putty is meant to be used over primer so apply after your primer coat of paint. The putty is actually thick primer and that's why it's applied after the primer. Squadron putty is meant to stick to the raw plastic. That's the difference between the two ;)

Why would primer from a spray can stick to a nose cone any better then primer from a tube (Bondo spot putty)?
 
Why would primer from a spray can stick to a nose cone any better then primer from a tube (Bondo spot putty)?

I don't know, it's what it does. It's designed to fill holes in primers that show up after a car has been primed. The solvents are formulated to bond with the primer. This is so a car painter does not have to re-bondo a tiny hole, they can fill it with the spot putty. If you want to know more read the instructions on the tube....I did....
 
Bondo spot putty is essentially talc in a chemical solvent for PAINT. It will bond better to a paint subsurface than a raw surface, I'm told, due to the uniform chemical surface of the softer paint than the harder plastic. True or not, actual cause or not, it seems to bear out in practice. It'll blend better when sanded, too, if applied over primer. Since Bondo is a car product, I'll trust the car guys to know how to use it best, and they all say primer, then spot putty.

Squadron putty is essentially liquefied poly styrene, and thus is chemically most suited to model type plastics as it's chemical solvent is the same as the base material. It'll attach to paint well, too.

Most plastic LP/MP nose cones are Poly Styrene, and generally get surface dissolved well by the solvents in Bondo spot putty and especially well by the purpose made Squadron putty. Thus, the general practice is putty then primer.

Most HP nose cones are Polypropylene or fiberglass, and not overly affected by solvents in general or at all (thus the common usage of adhesion promoter when painting them), so the general practice is primer then putty.

So, the order of application depends on the base material.
 
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Its highly recommended that with any Polypropylene nose cone that you use a plastic adhesion promoter before the primer, otherwise the paint will just peel off them easily (just peeling blue masking tape is enough to pull the paint).
 
I don't know, it's what it does. It's designed to fill holes in primers that show up after a car has been primed. The solvents are formulated to bond with the primer. This is so a car painter does not have to re-bondo a tiny hole, they can fill it with the spot putty. If you want to know more read the instructions on the tube....I did....

Bondo spot putty is essentially talc in a chemical solvent for PAINT. It will bond better to a paint subsurface than a raw surface, I'm told, due to the uniform chemical surface of the softer paint than the harder plastic. True or not, actual cause or not, it seems to bear out in practice. It'll blend better when sanded, too, if applied over primer. Since Bondo is a car product, I'll trust the car guys to know how to use it best, and they all say primer, then spot putty.

Squadron putty is essentially liquefied poly styrene, and thus is chemically most suited to model type plastics as it's chemical solvent is the same as the base material. It'll attach to paint well, too.

Most plastic LP/MP nose cones are Poly Styrene, and generally get surface dissolved well by the solvents in Bondo spot putty and especially well by the purpose made Squadron putty. Thus, the general practice is putty then primer.

Most HP nose cones are Polypropylene or fiberglass, and not overly affected by solvents in general or at all (thus the common usage of adhesion promoter when painting them), so the general practice is primer then putty.

So, the order of application depends on the base material.

This type of answer is just so much better then being told to read the instruction by someone that doesn't have the answer.

Thank you.
 
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