Build thread: Blackfish

[mbeels]

I like the larger text, I think that is an improvement. I also agree, a relatively simple and clean design without extra details suits this rocket well.

Are there 2 chevrons per pod? I'd be inclined to do perhaps just one per pod, facing radially outwards from the rocket.

 

[lakeroadster]

FWIW... I never sand the primer unless it needs it due to surface issues... but then again my finished painted rockets don't look nearly as good as yours.

Are you talking about filler/primer or regular primer? As mentioned above, I find it hard to envision leaving filler/primer unsanded. Regular primer, though, I usually don't sand (in fact I usually apply it in the same painting session as the base coat).

Both. Filler/primer and regular primer. I don't sand either unless there are issues that require sanding.

That primer texture is a good thing, some folks say you want the surface to have a "tooth" to it to ensure proper adhesion of the top coat.

 

[lakeroadster]

A question, do you NEED filler type primer on PAPERED surfaces? They should already BE pretty smooth, I would think the only purpose of primer over paper was better adhesion of the final paint layer (and even then, do you really need it?)

If I may be so bold as to add to this discussion... I was taught never to paint anything unless it has previously been primered... If you think about the pieces of a rocket and their individual surface finishes, some are smooth, almost glass like (like plastic nose cones) yet some components aren't smooth at all.

The primer covers every thing and gives it all one single surface finish. Then when you apply the top coat the end result is a uniform finish all over. Things like non primed wood filler will make a duller surface in the gloss top coat than the area without wood filler.

And those super smooth parts... don't have enough of a "tooth" to the surface for proper adhesion of the paint top coat. Primer sticks better to those surfaces than paint.

 

[neil_w]

Are there 2 chevrons per pod? I'd be inclined to do perhaps just one per pod, facing radially outwards from the rocket.

It's actually three chevrons wrapped all the way around. With one, it'd look like this:



Here it is with the single chevron somewhat larger, which is probably better:


My initial reaction is that I like it better with the full wrap, but I'll await other opinions.

 

[neil_w]

If I may be so bold as to add to this discussion... I was taught never to paint anything unless it has previously been primered... If you think about the pieces of a rocket and their individual surface finishes, some are smooth, almost glass like (like plastic nose cones and some aren't smooth at all.

The primer covers every thing and gives it all one single surface finish. Then when you apply the top coat the end result is a uniform finish all over. Things like non primed wood filler will make a duller surface in the gloss top coat than the area without wood filler.

And those super smooth parts... don't have enough of a "tooth" to the surface for proper adhesion of the paint top coat. Primer sticks better to those surfaces than paint.

The Rusto 2x is allegedly paint-and-primer in one. I've never had trouble with it sticking to anything. That said, there are some situations where I would always use primer anyway, like on plastic parts.

 

[lakeroadster]

I like the single... or maybe no chevron at all on the pods

 

[neil_w]

The single larger chevron is growing on me. I do want something orange there.

 

[mbeels]

It's actually three chevrons wrapped all the way around.

ok, I thought it was drawn with 2, one on each side with the fin surface. I do like the single larger chevron.

 

[neil_w]

ok, I thought it was drawn with 2, one on each side with the fin surface. I do like the single larger chevron.

Sold. It'll be much easier to apply than the wrap, and it will accomplish my goals for the design there.

Now I have to decide if I want to wait until I can get back to the office to laser-print the decals, or have another go with inkjet-printed (although I think my gloss clear is in the office as well). Probably wait until I can do the laser, likely within the next week or two.

 

[Charles_McG]

Circling back to paint adhesion - I have a terrible time getting 2X to stick to CA. Repairs, papering, or hardening. How do you do it?

 

[neil_w]

Circling back to paint adhesion - I have a terrible time getting 2X to stick to CA. Repairs, papering, or hardening. How do you do it?

Hmm, I may not have a good answer for you here. I haven't done a lot of CA I think I did a bit on Alcubierre and the paint stuck to it OK (brushed on). The touch-up is not in a high-wear location, though, so it's not taking any abuse, and the rocket doesn't fly often.

Anywhere else I might have had exposed CA on a build, I didn't experience any problem. Never did anything special. But it would normally only be small areas, as far as I can recall.

 

[BABAR]

Does thin (or other) CA go on smooth, evenly and sand down smooth over large regions of paper? I am thinking the cheap Hobby Lobby stuff.

Seems to me one of the “hazards” of papering with glue instead of self adhesive paper is getting glue (in this case white glue, but seems like when I have spilled CA on paper it messes it up and I have a hard time getting it smooth again, which is the whole point in papering in the first place other than strength,)

 

[Greg Furtman]

I get some clogging with the 400-800 grit paper. When I wet sand, the whole final sanding process is so much easier and faster, and the results are much improved. Instead of just "smooth", I get an almost glassy result with much less work.

I hear recommendations to not wet sand on a cardboard rocket, but the results are just so much better. I see no reason to *not* wet sand the primer.

Even if you're dry sanding and get through to the paper you get scuff marks, so either way (dry sanding or wet) the paper needs a layer of primer over it.

Edit: I think his specific concern is that primer is porous, so that some water gets through to the paper or cardboard underneath. If that does happen, it dries out and there is no ill consequence.

@mbeels Try using the same grit ScotchBrite pad. I use the maroon colored ones which is about 320 grit. Since it is thick unlike sandpaper it doesn't clog up and when it does you can soak it in mineral spirits to clean it up. Think 3D sandpaper.

 

[mbeels]

@mbeels Try using the same grit ScotchBrite pad. I use the maroon colored ones which is about 320 grit. Since it is thick unlike sandpaper it doesn't clog up and when it does you can soak it in mineral spirits to clean it up. Think 3D sandpaper.

Sounds like an interesting possibility, how does it do with contours and nooks and crannies?

 

[neil_w]

@mbeels Try using the same grit ScotchBrite pad. I use the maroon colored ones which is about 320 grit. Since it is thick unlike sandpaper it doesn't clog up and when it does you can soak it in mineral spirits to clean it up. Think 3D sandpaper.

I really need to try that stuff. Could be ideal for sanding large areas like body tubes and large fins, and then switch to sandpaper if necessary for nooks and crannie.

 

[jqavins]

Of course, all statements are prefaced with "In my opinion..."

1. The bigger letters are an improvement.
2. For the pod chevrons, you might try the one large per pod, but oriented a bit differently. From the first picture I could only see the chevrons that face the same way as the lettered decals; what you might try is that for the two fins I saw, and 180° from that for the third, which puts it radially out from its fin.
3. I think I'd like to see just a tiny bit of color at the aft tips of the pods. Nothing more than a dot, right on the tip. Maybe white, maybe deep red, maybe blue. I don't know, just something not black or orange. A little dot.

 

[jqavins]

nooks and crannie.

Every time I see that phrase I think there ought to be a crime novel - caper, mystery, what have you - called Crooks and Nannies. It could be part of a series with my other crime novel title, Death and Texas. Maybe a whole series of anagram and spoonerism based titles. The shame of it is that I have not a shadow of a notion for story ideas to go with them, nor interest in writing crime novels.

And now, back to rockets...

 

[neil_w]

Hey those are pretty good.

 

[Greg Furtman]

Sounds like an interesting possibility, how does it do with contours and nooks and crannies?

Works better than sandpaper.

 

[neil_w]

1. For the pod chevrons, you might try the one large per pod, but oriented a bit differently. From the first picture I could only see the chevrons that face the same way as the lettered decals; what you might try is that for the two fins I saw, and 180° from that for the third, which puts it radially out from its fin.
2. I think I'd like to see just a tiny bit of color at the aft tips of the pods. Nothing more than a dot, right on the tip. Maybe white, maybe deep red, maybe blue. I don't know, just something not black or orange. A little dot.

The Chevrons are all radially outward. That's the only way that really makes sense if there's only one of them (at least, if you favor symmetry, which in this case I do). As for color on the tip of the pod... white and orange are the only options, and right now it looks like I won't be buying orange paint, so white is the only option. Probably won't do it, but I'll fiddle in OR just a bit more to see if it makes sense.

 

[neil_w]

White tips, with and without:

 

[jqavins]

That's the only way that really makes sense if there's only one of them (at least, if you favor symmetry, which in this case I do).

If you like trilateral symmetry, as defined by the fins. There would still be bilateral symmetry to the chevron placement. Combining trilateral and bilateral symmetry in a single visual design creates a built-in contrast, which can be very pleasing to the eye, while evoking a sense of [insert pretentious design related psychobable]...

But then, it's not what you want, so screw it.

White tips, with and without:
View attachment 420893
View attachment 420894

Nice, but is this if in response to my suggestion, I was talking about the aft tips, the pointy ends. And in my mind, even smaller.

 

[neil_w]

Nice, but is this if in response to my suggestion, I was talking about the aft tips, the pointy ends. And in my mind, even smaller.

Doh! Reading comprehension fail.


Background set to grey for contrast. Also note the wrong chevron design is shown at front of pods (OR issue, don't ask).

 

[jqavins]

Yup, looks as good (to me) as it did in my head.

 

[neil_w]

Just fiddling and experimenting a bit.

[note: fixed positioning, and also found and corrected a huge decal error that would have been a major bummer. The body decal is a bit smaller now, as large as can fit on an 8.5x11" sheet. I wish it could be a bit longer but I don't want to split it into pieces.]

Not sure how I feel about the white point on the transition, but it does pull together the white pod tips a bit.

 

[hcmbanjo]

I tried to answer all your questions. Your quotes are in italic -
Questions from Neil W -
"Valid questions. Let's have a go:
I am mostly using the finishing strategy that @hcmbanjo has documented on his blog. In this strategy, filler/primer is functioning primarily as filler. So you sand off just about all of it except what remains in the various cracks and indentations, and then it has done its job. The reason to remove as much of it as possible is.... well, I guess it's mostly about weight, but perhaps also a bit of thickness, although I can't attach any numbers to either of these. A good area for experimentation."

Hi Neil,
I do a two step fill. First is the CWF to fill 80% of the balsa grain and tube seams. The second step Duplicolor Filler/Primer fills any remaining grain and seams after sanding.
Removing most all of the filler/primer is not for weight reduction. I'm a sport flyer, a little extra weight doesn't bother me or my flights.
This two-step fill process is something that works for me - In my teens, I hated the four passes of brush on and sand steps using sanding sealer. I read about some multiple step process some builders employ and wonder how long it takes them to finish a rocket.
My fill and finish steps are probably quicker. What slows things down is the paint dry times between finish colors.
I have used every available filler/primer out there and have found the automotive Duplicolor Filler/Primer to be the best. Some filler/primers sand like rubber!

"In general, I'm not as obsessive about removing filler/primer as Chris is; his body tubes in particular have *very* little grey left on them when he's done with them. I tend to run out of patience before I get to that point, but my mindset has still been to remove "most" of it."

You probably don't have to take it down to the tube and balsa surface like I do, but this works for me. When you sand to surface you will see gray filler/primer left in the remaining seams and balsa grain.

"I am definitely leaning towards the idea of leaving a bit more primer on in areas where scuffing is a danger. That might help avoid problems. However, sand-through is still possible at high points. I guess if I can just minimize them, then a bit of touch-up here and there with CA is no biggie."

Occasionally I do sand too much and can scuff the surface. This shows up when I shoot the first gloss white coats. I usually do a gloss white undercoat. Take the undercoated model out in the direct sunlight and you'll see the rough spots that require smooth sanding. There are always some rough areas and glue boogers that need to be smoothed out.
If an area was rough or sanded through, I do some light sanding of those areas of the white base coat. These (sanded) rough areas disappear with the second white undercoat.

"I can't imagine leaving filler/primer unsanded. After a heavy coat, it's usually quite rough and bumpy. However, the idea of performing minimal sanding only to smooth it out definitely is something I'll explore, rather than trying to remove most of it."
"Are you talking about filler/primer or regular primer? As mentioned above, I find it hard to envision leaving filler/primer unsanded. Regular primer, though, I usually don't sand (in fact I usually apply it in the same painting session as the base coat).

The Duplicolor Filler/Primer I use drys dull and slightly rough. At a minimum you do have to lightly sand to smooth it out.
I only use the Duplicolor Filler/Primer (FP101) then sand to surface. No other "Primer" after that, just the white undercoats.

Here's the process I use:
Filling the grain and tube seams:
1. Thinned Elmers Carpenter's Wood Filler (CWF) from the orange lid tub.
1A. Sand (leaving a very slight beige skin of CWF on the surface with 400 grit.
If you see the "pink" balsa showing through you may have sanded too much.
2. Fairly thick spraying of Duplicolor Filler/Primer
2A. Sand filler/primer to surface with 400 grit.

Spray Painting:
3. Gloss white undercoat light spraying
3A. Lightly sand any rough spots with 800 grit. Look close at surfaces in direct light and smooth out leftover any 400 grit scratches.
3B. Second gloss white undercoat, heavier sprayed if first undercoat is good.
The heavier final coat is tricky. Heavy enough to really cover, not so much as to create drips.
4. Let dry for a minimum of 48 hours, longer if you can still smell the paint.
Plastic nose cones and plastic parts require longer drying times!
Mask and follow with secondary colors.

I hope that answers your questions. I would never say: "It's my way or the highway."
Everybody has a different method. This is what works for me.

 

[neil_w]

Chris,
Thanks for weighing in. One follow-up:

I do a two step fill. First is the CWF to fill 80% of the balsa grain and tube seams. The second step Duplicolor Filler/Primer fills any remaining grain and seams after sanding.
Removing most all of the filler/primer is not for weight reduction. I'm a sport flyer, a little extra weight doesn't bother me or my flights.

In that case, what's it for? It would be less effort and sanding to just smooth off the filler/primer layer rather than removing most of it as you do, wouldn't it?

I hope that answers your questions. I would never say: "It's my way or the highway."
Everybody has a different method. This is what works for me.

Your way works extremely well, and has been the foundation of all my builds since I restarted. Sometimes just curious about reason for doing certain things.

 

[hcmbanjo]

One follow-up:
hcmbanjo said:
I do a two step fill. First is the CWF to fill 80% of the balsa grain and tube seams. The second step Duplicolor Filler/Primer fills any remaining grain and seams after sanding.
Removing most all of the filler/primer is not for weight reduction. I'm a sport flyer, a little extra weight doesn't bother me or my flights.

"In that case, what's it for? It would be less effort and sanding to just smooth off the filler/primer layer rather than removing most of it as you do, wouldn't it?"

In the past I've noticed spiral seams (looking close at the final color coats) if I don't sand down an remove most all of the filler/primer.
Like I've mentioned, I use it as a filler, not so much as a primer.
Some say primer helps paint adhesion. I rarely have problems with paint staying on the surface.
That only happens on some plastics. Body tubes and fins are porous and the paint adheres well.

 

[neil_w]

DRY FITTING THE RINGS

Let's see what those rings look like.

First I slit them with scissors. Doing so with a knife would have been tricky; scissors make a clean straight cut in a second. I note that now, the rings did not expand at all when cut. Good.


Next I slide them into place, and they looks like this:

Fit seems good, they should glue in easily. Just need some white paint. ARGH.

Now, how do they look? Well, roughly as expected and planned, I'd say. I'm not sure the bevels improve the look proportional to the effort it took to implement them, but they are pretty distinctive and certainly don't look *bad*. Plus, anything that adds extra effort to the build is probably a plus just on principle.

 

[mbeels]

That looks awesome! I love that bevel in the rings (salami cut??) The black and white contrast really makes them pop.

Plus, anything that adds extra effort to the build is probably a plus just on principle.

I agree with that.