High temperature paint

[Walter Longburn]

Has anyone here used VHT high temp paint, Rust-oleum high heat primer, or Rust-oleum high heat clear coat? These paints are supposed to be heat cured but I was wondering if I should just try it without. I'm building a rocket that may go somewhere around Mach 2.8 and if the paint is going to blister I'd rather not paint it.

Are there paints you've used with good results at similar speeds?

 

[Walter Longburn]

https://www.amazon.com/VHT-SP110-FlameProof-Coating-Paint/dp/B000CPCRDG
https://www.amazon.com/Rust-Oleum-Automotive-260771-11-Ounce-Degrees/dp/B006ZLQ0JI
https://www.amazon.com/Rust-Oleum-249340-Automotive-12-Ounce-Primer/dp/B003CT499O

 

[BABAR]

I wonder if at times people have the wrong expectations of high temp paints.

I think the manufacturers of these are saying, you can use this paint on something that is AREADY heat resistant, like the outside of a metal barbecue kettle or maybe some sort of motorcycle engine pipe. And the paint won’t burn off like standard paints.

but I wonder if (some) people on the rocketry side are thinking, if I paint this over balsa or plastic, the paint will protect the underlying substrate. My suspicion is most likely that doesn’t work. I may be wrong, it happens frequently.

 

[Walter Longburn]

This rocket is fiberglass with a wildman High temp fiberglass nose cone and some carbon fiber on the fins. I am mostly worried about it blistering on the nose cone and if that happens it will probably cut the apogee down by a couple thousand feet.

I already know if I use regular paint it WILL blister.

 

[Walter Longburn]

So for those of you who regularly do Mach 2+ do you paint the nose cones?

 

[tfish]

For my rockets that I want to squeeze the last little bit of altitude out of them..I do not paint them
Paint adds some OD to the rocket
Paint adds some weight to the rockets
the paint will probably melt and add drag to the rocket.

Tony

 

[watheyak]

I haven't had luck with any paint above Mach 2.7.

I'm contemplating just polishing the bare FG of the Wildman high temp nosecone on my current project.

 

[icyclops]

I wonder if at times people have the wrong expectations of high temp paints.

I think the manufacturers of these are saying, you can use this paint on something that is AREADY heat resistant, like the outside of a metal barbecue kettle or maybe some sort of motorcycle engine pipe. And the paint won’t burn off like standard paints.

but I wonder if (some) people on the rocketry side are thinking, if I paint this over balsa or plastic, the paint will protect the underlying substrate. My suspicion is most likely that doesn’t work. I may be wrong, it happens frequently.

Correct. Just about every HT paint does is be able to withstand a rated temperature that the paint is not suppose to burn or blister. It will not provide the protection to the under substance that is conducting or absorbing the heat….that is why baffles will still burn and wear out as the card stock behind the HT paint will give up first after multiple uses. Look at the temp rating for the paint…if Mach 2.8 generates heat over that level, then chances are it will show some form of heat deterioration.
However, some of the newer ceramic infused paints may provide better protection to the under surfaces…think of the ceramic coated heat tiles on the space shuttle….but regular HT paints provide limited protection for roc models.

 

[Ronz Rocketz]

For my rockets that I want to squeeze the last little bit of altitude out of them..I do not paint them
Paint adds some OD to the rocket
Paint adds some weight to the rockets
the paint will probably melt and add drag to the rocket.

Tony

Makes sense. Would some paint over FG reduce friction?

 

[tfish]

Makes sense. Would some paint over FG reduce friction?

I thinks it's easier to get a glass finish on bare FG/carbon items, compared to a painted surface.

Something does change drastically around mach 2.7 http://groveraerospace.com/?page_id=1538
regular rustoleum bubbles and melts around 2.3
regular paint or high temp paint bubbling, melting charring is doing some protecting of the under laying surface.
The question is ..at what temp does the under laying surface start falling apart?
How fast are you going?
can you add..normal construction/build bulk (thickness) to maintain structure integrity.
what can current nose cones, fin materials and fin attachment (1/3 - 2/3 layups) take
ablatives made with 'good' epoxies and glass micro balloons or powdered cork...test at home.

Tony

 

[Steve Shannon]

I would still paint the rocket body in a bright color to make it easier to see lying in the distance. I probably wouldn’t bother painting the leading surfaces where the paint will just ablate. There’s no point to achieving an extra 2k’ altitude if you cannot find your rocket afterwards.

 

[Hobie1dog]

Yep, I would use VHT Hi-Temp/header paint, as it will NOT blister.

 

[mtnmanak]

I have had good results from Duplicolor Engine Enamels. They coat well and dry fast. I have not pushed anything over Mach 2.7, but I have pushed some to above Mach 2 and they didn't have a mark on them.

The biggest issue I have had with these paints are they are very susceptible to cold and humidity. Especially cold. I would not try to apply these paints in temps less than 65 degrees. It isn't probably an issue in the summer, but I tried to paint a couple rockets over the winter and the paint had big discoloration spots in it when I tried to apply the paint under 60 degrees.

 

[Walter Longburn]

Yep, I would use VHT Hi-Temp/header paint, as it will NOT blister.

What worries me is that I won't be able to heat cure it like it is supposed to be. 250F for 30 minutes, let it cool for 30 minutes, 400F for 30 minutes, let it cool for 30 minutes, and then 600F for 30 minutes.

 

[SkywackerJim]

Wonder what paint they use on fighter jets?

 

[watheyak]

Keep in mind that heat isn't the only issue here. Most barbecues and headers don't go 2000mph.

And if you're going Mach 2.5 you can probably paint it with any good quality paint without issue. But for whatever reason, M2.7 and above is a different ballgame.

 

[blackjack2564]

Nc before...before anything


Nc after 2 coats high temp epoxy polished 900 degree rated. Replaced metal tip with phenolic.



before flight..rusto bar b due white [1200 degree] for primer and engine orange 500 degree finish


what M-2.87 does..lol some of high temp paint primer still on fins...[.all carbon but nc] nothing left on NC...lol Over mach for 12 seconds.


epoxy ablated off most tip

 

[watheyak]

Sexy! The rocket’s pretty cool too.

 

[OzHybrid]

Nc before...before anything
View attachment 471941

Nc after 2 coats high temp epoxy polished 900 degree rated. Replaced metal tip with phenolic.

View attachment 471942

before flight..rusto bar b due white [1200 degree] for primer and engine orange 500 finish
View attachment 471943

what M-2.87 does..lol some of high temp paint primer still on fins...[.all carbon but nc] nothing on NC...lol Over mach for 12 seconds.
View attachment 471945View attachment 471946

epoxy ablated off most tip

Proper empirical data. Like it.....! This is going straight to the pool room!!!!!

 

[blackjack2564]

If nothing else it shows you where the shockwaves and heat buildup are.

 

[boomtube-mk2]

Has anyone tried "Dupli-Color" high temperature engine enamel with ceramic?

I've used it solely because I've gotten great results with the finish and they have some neat colors.