Drag

[Hugh Cronin]

Same rocket stock no paint vs all painted and polished with same engine. What would be altitude difference.

 

[Eric]

Using simulation programs, they let you pick the surface finish. A smooth finish compared to a rough finish can easily be a 10 to 20% gain in altitude

 

[Nytrunner]

Using simulation programs, they let you pick the surface finish. A smooth finish compared to a rough finish can easily be a 10 to 20% gain in altitude

, minus a tad for the added weight of the primer/spot filler/paint/wax etc...

 

[lakeroadster]

I just threw up a bit... now we know why your avatar is "stealth6"....

 

[Hugh Cronin]

I’m done here.

 

[stealth6]

Ok folks, I'll apologize for my (now deleted) post.

Honestly, it was meant to be just a little chuckle, nothing at all with the intention to offend, cause ill will, be mean, or to stir up any trouble. I'm quite frankly surprised at such a strong reaction. But I'll take it seriously and sincerely apologize to anyone who was offended. My bad, I'll take the blame, and file this under "a stupid thing for me to post".

Hugh....don't go away. I'll be nice from now on.

s6

 

[stealth6]

Hugh......a more serious response to your OP:

Keep in mind that when a sim program uses "polished" as a surface, it means REALLY polished. Not just "shiny and smooth feeling". It is absolutely achievable, and absolutely will give you greater altitude, and it is worth doing if you care about max performance. Assuming you have a surface finish ("paint") that can take any excess heat that may be involved in a super high performance flight, a properly worked painted surface will probably be capable of higher polishing than bare fiberglass (but not metal). But realize that to get there, you need to "finish the finish"....there are no paints will come out truly polished in just curing. Even the ones that are "super high gloss" or some other marketing jargon. It's a fair amount of work to do correctly, but again if you really want max performance, it's worth it.

s6

 

[dr wogz]

Something else to consider, is that induced drag due to part misalignment or the like will also rob you of the utmost altitude. the Sims assume a perfectly built & aligned model, with no overhang, hairs, divets, dents, fins misaligned, etc..

 

[Bat-mite]

Hugh......a more serious response to your OP:

Keep in mind that when a sim program uses "polished" as a surface, it means REALLY polished. Not just "shiny and smooth feeling". It is absolutely achievable, and absolutely will give you greater altitude, and it is worth doing if you care about max performance. Assuming you have a surface finish ("paint") that can take any excess heat that may be involved in a super high performance flight, a properly worked painted surface will probably be capable of higher polishing than bare fiberglass (but not metal). But realize that to get there, you need to "finish the finish"....there are no paints will come out truly polished in just curing. Even the ones that are "super high gloss" or some other marketing jargon. It's a fair amount of work to do correctly, but again if you really want max performance, it's worth it.

s6

See any build thread by Nathan if you want to see what polished looks like.

 

[David Schwantz]

Hugh......a more serious response to your OP:

Keep in mind that when a sim program uses "polished" as a surface, it means REALLY polished. Not just "shiny and smooth feeling". It is absolutely achievable, and absolutely will give you greater altitude, and it is worth doing if you care about max performance. Assuming you have a surface finish ("paint") that can take any excess heat that may be involved in a super high performance flight, a properly worked painted surface will probably be capable of higher polishing than bare fiberglass (but not metal). But realize that to get there, you need to "finish the finish"....there are no paints will come out truly polished in just curing. Even the ones that are "super high gloss" or some other marketing jargon. It's a fair amount of work to do correctly, but again if you really want max performance, it's worth it.

s6

Check out post #1 in HPR under "3" Black Hole" I think you may be mistaken!