Filling Body Tube Spirals

[Tau Zero]

Hey, Bill!

I recall reading (probably in one of your numerous EMRR reviews) that you filled body tube spirals with thinned "Fill N' Finish." I've already sprayed some tubes with 2 layers of primer, followed by sanding after each coat. :D

What consistency should I make the "filler?" :confused: I don't want to get it too thin, because then the water would (obviously) soak into the non-waterproofed body tube.

So spill, already. :eek:


Thanks, buddy!

--Jay

[A Fish Named Wallyum]

As long as I've shot a coat of primer on first I've never had a problem. I didn't even have trouble before I adopted the "Prime First" philosophy. I make it the consistency of yellow glue or slightly thicker.

[CPMcGraw]

Hey, Bill!

I recall reading (probably in one of your numerous EMRR reviews) that you filled body tube spirals with thinned "Fill N' Finish." I've already sprayed some tubes with 2 layers of primer, followed by sanding after each coat. :D

What consistency should I make the "filler?" :confused: I don't want to get it too thin, because then the water would (obviously) soak into the non-waterproofed body tube.

So spill, already. :eek:


Thanks, buddy!

--Jay

Jay [and Bill],

I know you directed this to Bill, but this is also the method I use. Hope you guys don't mind my intrusion... ;)

I actually thin my FNF quite a bit, not quite 'watery thin', but thin enough that I can spread it easily with a hobby brush. Maybe a bit thinner than cream soup. I also sand the tube first until the outer layer of glassine is "flat", or all of the gloss has been removed. You should actually be raising a powder from the surface. This lets the FNF 'bite' into the paper, as well as making the spiral groove lower in profile. The FNF doesn't have so much water in it that it damages the tube, but you do need the compound to work its way into the fibers, and it can't do that when it's thick.

Here's where I differ with Bill: DON'T apply this OVER the primer -- it won't adhere as well, because it doesn't have the chance to get into the fibers of the paper, and could fall out of the cracks after it's been painted. You want the FNF anchored to the paper.

Don't be afraid to thin the FNF a little more than you think is reasonable. As long as you're not immersing the tube into the FNF tub to soak, you're not going to damage the tube. I suppose if you were using really thin-walled tubes, you might have a problem. But for modern Estes, SEMROC, or Quest tubes (Euclid tubes) you don't have a lot to worry about. Slather it on the whole tube liberally. When this dries fully and you sand it with 220-grit, the tube should now be completely 'stained' to a light tan. This is a good indicator you've adhered to the tube. Depending on how bad the spiral started out, you might need a second "spot application" of slightly thinned, or even full-strength, FNF on those areas before you prime the tube. But this is usually all you need to do before priming.

$0.02 worth, with interest...

Craig...

[A Fish Named Wallyum]

And don't use the tube as a straw to drink the FNF. It tastes bad and doesn't take the spirals out of the colon as advertised.
Never thought about the possibility of the FNF not reacting well with the "primer first" school of thought. Like I said, I've done both and have never had a problem. I also sand the tube beforehand.

[ShieldWolf]

I simply add a little water directly to the container of FnF and use a 1" foam brush to stir it up so that I have a layer of FnF about the consistency of house paint. I then paint that onto the fins and spirals. Once it has dried, I sand everything smooth, and repeat the process for any remaining low spots.

Putting water directly into the tub seems to help avoid getting a layer of dry, crusty, FnF.

Randal

[dtomko]

And don't use the tube as a straw to drink the FNF. It tastes bad and doesn't take the spirals out of the colon as advertised.
.
This brings new meaning to the term "high-colonic," but I digress.
I use Elmer's wood filler that is white and comes in a tube. It's already thinner than F'n F. I thin it a little more. You can get absorption into the BT if you are not careful with this stuff. One way to avoid this is to line the spiral on both sides with maksing tape. That's usually too tedious for me, so I run the stuff in with my finger and scrape most of it off with a flat piece of styrene. I usually go over it once more to get the spots that are missed, but that's enough with a coat of primer.
Drew Tomko

[CPMcGraw]

I simply add a little water directly to the container of FnF and use a 1" foam brush to stir it up so that I have a layer of FnF about the consistency of house paint. I then paint that onto the fins and spirals. Once it has dried, I sand everything smooth, and repeat the process for any remaining low spots.

Putting water directly into the tub seems to help avoid getting a layer of dry, crusty, FnF.

Randal

That's my method, too. I keep about 1/4" of liquid on top all the time.

I stir it up with the brush just before using it, scraping a layer of thicker material up as needed. When it settles down again, you're back to a layer of just water on top...


Craig...

[CPMcGraw]

Never thought about the possibility of the FNF not reacting well with the "primer first" school of thought. Like I said, I've done both and have never had a problem. I also sand the tube beforehand.

Think of FNF in the same way as applying a "double glue" fin joint. The first application of FNF [thinned] locks into the fibers of the paper, the second application adheres to the first layer. If you prime the tube first, you've sealed up the gaps between the fibers, and the FNF only has "surface adhesion" to a slick surface after that. YMMV...

The primer should be used to seal the FNF, and should be the only surface that the final color coats actually come in contact with.


Craig...

[Tau Zero]

Think of FNF in the same way as applying a "double glue" fin joint. The first application of FNF [thinned] locks into the fibers of the paper, the second application adheres to the first layer. If you prime the tube first, you've sealed up the gaps between the fibers, and the FNF only has "surface adhesion" to a slick surface after that. YMMV...

The primer should be used to seal the FNF, and should be the only surface that the final color coats actually come in contact with.Dear Bill, Craig, Drew, and Randal,

Thanks so much for everybody chiming in on this! :D The Semroc ST-5 body tubes I've gotten seem to have a much more pronounced "groove" compared to the classic Estes BT-5 tubes. But since I've recently been trying to discipline my building habits by using Semroc tubes exclusively for some specific building projects... (heavy sigh of resignation) :rolleyes:


So if I build a version of Pete Alway's "Saturn IV" with Semroc ST-13 and 16 (instead of Estes BT-55 and 60), but still opt for Estes BT-5's... well, you'll know why. ;)


Cheers,

--Jay
"Centuri Guy"

[Tau Zero]

So if I build a version of Pete Alway's "Saturn IV" with Semroc ST-13 and 16 (instead of Estes BT-55 and 60), but still opt for Estes BT-5's... well, you'll know why. ;) http://members.aol.com/petealway/models.html

Scroll down to rocket #7, where you can download 2 pages of the plans and patterns.

--Jay

[Ltvscout]

I also sand the tube first until the outer layer of glassine is "flat", or all of the gloss has been removed. You should actually be raising a powder from the surface. This lets the FNF 'bite' into the paper, as well as making the spiral groove lower in profile.
Craig,

Do you use 220-grit for this initial sand as well?

[CPMcGraw]

Craig,

Do you use 220-grit for this initial sand as well?

For the initial sanding, yes. It's not so coarse that it cuts down into the fibers of the paper, but it is aggressive enough to cut the glassine layer. You can *raise powder* quite easily with 220, both with the white [Euclid] tubes and the old-style brown tubes...

I've found 220-grit is also a good general purpose paper for doing not only the glassine sanding, but for the first balsa sanding and the first few primer sandings. Once the primer looks smooth, like after the second or third coat, then I switch to 400-grit, spray a coat, and finally switch to a 600-grit for the final sanding. I don't take it down any farther than 600, but I suppose one could for a laquer-based finish...


Craig...

[Tau Zero]

Okay, I just spent awhile looking back at this thread, and I think I've boiled down the process to "Almost 3 (okay, 4) Easy Steps!" ;) :rolleyes:

1. Using 220 grit sandpaper, sand "naked" body tube.

I also sand the tube first until the outer layer of glassine is "flat", or all of the gloss has been removed. You should actually be raising a powder from the surface.

2. Apply Fill N' Finish.

This lets the FNF 'bite' into the paper, as well as making the spiral groove lower in profile. The FNF doesn't have so much water in it that it damages the tube, but you do need the compound to work its way into the fibers, and it can't do that when it's thick.

DON'T apply this OVER the primer -- it won't adhere as well, because it doesn't have the chance to get into the fibers of the paper, and could fall out of the cracks after it's been painted. You want the FNF anchored to the paper.

Don't be afraid to thin the FNF a little more than you think is reasonable. [snip] Slather it on the whole tube liberally.
When this dries fully and you sand it with 220-grit, the tube should now be completely 'stained' to a light tan. This is a good indicator you've adhered to the tube. [snip] But this is usually all you need to do before priming.

3. Sand excess Fill N' Finish with 220-grit sandpaper.

4. Apply primer to body tube, sanding after each coat.

Now, I think I can patter off on my merry little way... :cool: --Yes? :confused: :eek:


Cheers,

--Jay

[CPMcGraw]

Okay, I just spent awhile looking back at this thread, and I think I've boiled down the process to "Almost 3 (okay, 4) Easy Steps!" ;) :rolleyes:

1. Using 220 grit sandpaper, sand "naked" body tube.
2. Apply Fill N' Finish.
3. Sand excess Fill N' Finish with 220-grit sandpaper.
4. Apply primer to body tube, sanding after each coat.

Sounds like a plan, Jay.

For catalog-finish models, you might repeat steps 2 & 3 "as needed". FNF sticks to itself reasonably well...

Since I don't yet have a catalog to finish, I usually just apply FNF once...:D

[Tau Zero]

For catalog-finish models, you might repeat steps 2 & 3 "as needed". FNF sticks to itself reasonably well...

Since I don't yet have a catalog to finish, I usually just apply FNF once...:DYeah, but you know *me,* Craig. If I wasn't so stinkin' picky about my finishing techniques in my second incarnation as a rocketeer, I'd actually get more rockets *built*... ;) :D ...*If* ya know what I mean. :eek: :o


Cheers,

--Jay

[Enign Blather]

I can't seem to find this Fill N Finish anywhere. All the shops around me have is the heavyier crap- E832, et. all.

There is one hobby shop that has a Hobbico product. It looks like spackle and has "Micro-balloons". Anyone know if this will work as well as FNF?

Thanks,
EB

[Eagle3]

No, micro balloons isn't the same. I've used micro balloons mixed with epoxy to make fillets, but it won't work like Elmer's FnF. My FnF (light wood filler in a 16 oz round tub) is almost out. I was in Lowe's the other day and found it, but in a rectangular 16 oz tub now. It appears to be the same stuff.

[Enign Blather]

OK then - no micro ballons it is then. I'll try lowe's. Thanks!

[HighPowerKid]

I just got done filling a tube for my LOC Isis. I add a little water to Elmers Wood Filler and it works great. Also doesnt take very long.

[Royatl]

No, micro balloons isn't the same. I've used micro balloons mixed with epoxy to make fillets, but it won't work like Elmer's FnF. My FnF (light wood filler in a 16 oz round tub) is almost out. I was in Lowe's the other day and found it, but in a rectangular 16 oz tub now. It appears to be the same stuff.

No, he's saying the stuff from Hobbyco has micro-balloons in it just like the Elmer's FnF does, but you're right in that the FnF is much better for the job than the Hobbyco stuff.

[Royatl]

I can't seem to find this Fill N Finish anywhere. All the shops around me have is the heavyier crap- E832, et. all.

There is one hobby shop that has a Hobbico product. It looks like spackle and has "Micro-balloons". Anyone know if this will work as well as FNF?

Thanks,
EB


No, it isn't as good, but if you can't find FnF, it may be better for the job than the other Elmer's fillers.

[Rocketking]

Regarding filling the spiral on BT's, There was a product called Carpenter's Wood Filler, which was renamed "Fill & Finish Exterior Filler", There is 'give' which allows it to bond better to the flexible body tube. The Fill and Finish interior Filler is better used for filling the grain of balsa fins. These two products are better thinned with water to a mixture two parts putty to one part water. Use less water as it can weaken the body tube and/or warp the balsa fins. When used on balsa, apply to the same area on both sides of the fin to reduce the likelihood of warping.

I have found these in both Home Depot & Lowes, and saw some at clearance price from K-Mart!

These products are great! give 'em a try.

Revision - Lowes no longer stocks this item (at least I didn't find it!). Will be looking at Home Depot tomorrow. To be continued.

[bikegod]

Has anyone ever tried standard white glue thinned with water before priminig? I was just wondering if it would work. I have the Testors putty, but it is way thick and difficult to handle then needs even more sanding. There were times that I used it that I contemplated just leaving the spirals showing thru the paint. I will need to fill the small space between the two tubes (seam joint).

[Royatl]

Has anyone ever tried standard white glue thinned with water before priminig? I was just wondering if it would work. I have the Testors putty, but it is way thick and difficult to handle then needs even more sanding. There were times that I used it that I contemplated just leaving the spirals showing thru the paint. I will need to fill the small space between the two tubes (seam joint).


I used thinned Elmer's on my very first model rocket 38 years ago. It is the only rocket I ever used it on. Any questions? :)

[ghrocketman]

Unless the rocket is something special, I just leave the spirals as-is before priming.
A good thick primer such as KILZ fills in the spirals after two coats to the point that one can barely see them.

[CPMcGraw]

Has anyone ever tried standard white glue thinned with water before priminig? I was just wondering if it would work. I have the Testors putty, but it is way thick and difficult to handle then needs even more sanding. There were times that I used it that I contemplated just leaving the spirals showing thru the paint. I will need to fill the small space between the two tubes (seam joint).

I'm going to throw a monkey wrench into the arena here, because I have for a long time been a promoter of the Elmer's FNF product. I think the Elmer's product is really good, especially with its water cleanup and thinning. FNF sands nicely into a powder when it has fully cured.

Having said this, I am this weekend trying out what I now call "FNF in a spray can". One of our other forum members mentioned using this in another thread some time ago, and I have since tried it out and find that by allowing the product to fully cure for about two days, I have a very good coat of sandable primer that fills the spiral on the first shot.

White-pigmented KILZ aerosol.

Understand, this is an oil-based product, and has that traditional oil-based "perfume" which may not be agreeable to some with breathing sensitivity. For cleaning up my hands from the overspray, I use an orange oil-based cleaner called De-Zolv-It. This cuts the Kilz right off my hands without irritating the skin, and it washes off with soap and water.

BG, you mention the joint line between two body tubes. One of the models I'm priming this weekend is an Estes #1271 Renegade, and it has this configuration. I managed to eliminate most of the inevitable gap during construction, but there was still a visible seam. The Kilz completely covered the seam and filled the imperfections. Kilz is thicker than other primers, so sanding is a must. As long as the primer has fully cured, you only need 220-grit paper (keep plenty on hand...) to remove the excess and still leave a nice surface. YMMV, but so far I've seen the spiral gaps completely filled in the first spray.

If you take the Kilz down to nearly bare paper, you can follow up with a traditional primer (like Rust-O-Leum's white Bare Metal Primer) which is thinner than Kilz, and has a finer-grained pigment. Kilz can be sprayed directly onto bare balsa and it will adhere beautifully. After sanding, you will have a difficult time seeing any wood grain; any that does show through will be a deep gouge that probably should have been filled with something else first, like a thick mixture of 30-minute epoxy and microballoons.

So far, I've sprayed about 20 models with Kilz, and I'm impressed with the results. This simplifies the finishing process by eliminating one step. You still have a lot of sanding to do before the paint is applied, so I won't say it reduces the overall time spent finishing a model. It does allow you to do double-duty with one product -- filling the balsa grain and the spiral gap, and priming the surface -- so there may be some time saved from waiting for the filler to dry before priming...

I'll try to give additional information as I work my way through this pile of ready-to-prime models...

[bikegod]

I just tried the Kilz, and considering my impatience it came out well.

I originally put too much on the seam and when I tried to sand it, it sloughed off leaving a big gouge. I normally paint in a large box but my model wouldn't fit properly so I was handling it by each end.

I ended up doing a lot of sanding and reprimering the whole thing. Lots of dust, but it even filled in the raised grain on the fins. The spirals didn't go away until I sanded them, but they did go away, and quite easily.

I am currently in the painting mode right now, fin colors first, then I will mask them and paint the two colors on the body tube.

Won't fly this weekend (since I tripped and tore up my ankle yesterday and am now on crutches). Some time off from work, so I get to hang out in my home office and work on the Screaming Mimi as well. That has been a pain in the butt to sand, but it's looking pretty much like the kit (changed the nose cone so I could steal it for my kit).

[Rocketking]

Has anyone ever tried standard white glue thinned with water before priminig? I was just wondering if it would work. I have the Testors putty, but it is way thick and difficult to handle then needs even more sanding.

Talking too much sanding, white glue doesn't sand too well. It clogs the sandpaper much too easy.

In lieu of FnF, I understand that spackle (standard wallboard/drywall filler) works well & sands well- It just produces a lot of dust, so clean up after yourself before priming!

[bikegod]

OK, now I am a huge fan of the Fill and Finish as well as the Kilz Primer.

But I hate balsa nose cones and transitions. The small parts (TR-520 and BNC-20) that I got had that fuzzy balsa finish out of the pack and sanding them any bit didn't make a difference. I have been "practicing" with the FnF, slathering it on, sometimes really thin sometimes thicker. At least if I get too much on it sands off pretty easily.

I will also recommend drywall sanding screens, they last longer and don't clog. Even when they get full of dust you can snap it clean. Must sand in circles though, it can leave slight grooves that shows up at final paint if you are not careful.