Static Electricity???

[OverTheTop]

I used it for epoxy bonding. Too unreliable so I didn't use it in the final build.

 

[kjhambrick]

Thanks for the instructions on how to Flame Polish Polyolefins, @OzHybrid.

Saved for further study and possible eventual application on a 'thin wall' 42 gram 38mm Blue Polypropylene LOC Nose Cone I acquired for my next rocket ...

All I wanted was a white one so I could leave it unpainted as I have often done in the past to avoid the issues of painting PP

I also bought an 'un-thin' 70 gram 38mm Black LOC Nose Cone when I bought the thin blue one.

Holy cow ! The dry mass of that 38mm rocket is only 214 grams without a nose cone !

sigh ... I don't suppose I'll ever need any nose weight no matter what I shove up the tail on this one ... sigh ...

Maybe I should practice flame polishing on the 70-gram black one ?

Gratuitus link that discusses the properties of HDPE -vs- PP and applications for each: Polypropylene vs. HDPE: Material Differences and Comparisons

Speaking of properties ... I wonder if flame polishing results in a measurable change in the chemistry of the plastic molecules on the surface of the flame polished object ?

I wish I still had access to an IR Spectrometer so I could pull a before -and- after sprectrum or two ( a mild hint for @OverTheTop to maybe run with )

Hmmm ... now that I think about it, you Aussies are pretty good at bringing the science into the art of rocket science ...

I suppose the costs of participation Down Under cull out all but the most talented and motivated from among all'y'all ...

Thanks again !

-- kjh

 

[jqavins]

It's specific to polyolefins. Polypropylene and polyethylene.

Yes, I understand that. And those same materials are notoriously hard to get adhesives to adhere to.

I used it for epoxy bonding. Too unreliable so I didn't use it in the final build.

Thanks. Maybe I'll give it a shot, but I won't plan to rely on it.

Speaking of properties ... I wonder if flame polishing results in a measurable change in the chemistry of the plastic molecules on the surface of the flame polished object ?

This technique for paint adhesion, yes. Genuine flame polishing, maybe? For some materials? I've never encountered this technique before reading this thread, but reading it carefully reveals that modifying the chemistry at the the surface is exactly the point, not improving the surface finish. Flame polishing is a way of smoothing the surface on materials including glass and others I can't name, but from the previous posts here, that's not what this is all about.

 

[kjhambrick]

Thanks, @jqavins ...

@OverTheTop and I went a little off-topic in another thread when we started talking about IR Spectroscopy ... I was kinda-sorta kidding a bit here in this thread about "measurable chemical changes" ... (*)

But thanks for pointing me toward the difference in flame treating polyolefins and flame polishing other materials.

Something new to learn about and to ponder !

-- kjh

(*) EDIT: but I would still like to see the IR Spectra before and after