epoxy or anything

Hi, I don't usually buy rocket specific supplies because there hard to find where I live. My question is does anyone know of any good epoxy or something similar I could use to fill the body spirals ect. that can be purchased at like home depot or Walmart? I was almost thinking of just lightly painting my whole rocky with wood glue and then sanding it for painting.

elmer's sandable wood filler watered down a little bit works great. I have also heard of using bondo spot putty for the same thing. Just about any sandable woodfiller should work fine.

This is what I got at Home Depot a few years ago (it lasts awhile ). Trouble is Elmers is constantly changing the wrapper and otherwise "improving" the formula. Avoid anything with "max" or "pro" in the name. Avoid anything with "wood fibers" in the ingredients. Works for me on cardboard airframes. Never tried any epoxy fillers.

There are many, many *MANY* pages on the web devoted to this topic: https://www.google.com/webhp?source...1&espv=2&ie=UTF-8#q=filling+body+tube+spirals.

As far as I know there is no rocket-specific supply for this. Elmer's Carpenter's Wood Filler (as samb says, avoid the Pro of Max stuff, you want the plain vanilla wood filler) and Bondo Spot and Glazing Putty seem to be the fillers of choice. I've been using CWF with hcmbanjo's recommended water mix ratio with decent success. I want to try the Bondo one day.

Squeegeeing off the excess (I use a dull single-edged razor blade) is key to avoiding a tedious amount of sanding later on.

neil_w said:

There are many, many *MANY* pages on the web devoted to this topic: https://www.google.com/webhp?source...1&espv=2&ie=UTF-8#q=filling+body+tube+spirals.

As far as I know there is no rocket-specific supply for this. Elmer's Carpenter's Wood Filler (as samb says, avoid the Pro of Max stuff, you want the plain vanilla wood filler) and Bondo Spot and Glazing Putty seem to be the fillers of choice. I've been using CWF with hcmbanjo's recommended water mix ratio with decent success. I want to try the Bondo one day.

Squeegeeing off the excess (I use a dull single-edged razor blade) is key to avoiding a tedious amount of sanding later on.

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Bondo makes a spreader that is cheap, has a flat edge and is flexible. The only reason why I have it is for fiberglass work (specifically spreading out peel ply). An expired credit or debit card would be my next choice. And yes... if you don't take 2 minutes to get the right amount of filler and cleaning up the excess, it will be 10s of minutes sanding it down to true later. Cardboard also doesn't like 100 grit...

The hard part is not creating too much work for yourself. Definitely not epoxy: it would be crazy hard to sand off the extra. Wood filler, and realize that whatever's not in the crack has to be sanded off.

Some of the real ace builders here (JohnCoker, dixontj93060) recommend something called Superfil (https://www.aircraftspruce.com/catalog/cmpages/superfil.php). Not sure if it's applicable to lower power models or paper tubes and definitely not an HD or Wally World item.

samb said:

Some of the real ace builders here (JohnCoker, dixontj93060) recommend something called Superfil (https://www.aircraftspruce.com/catalog/cmpages/superfil.php). Not sure if it's applicable to lower power models or paper tubes and definitely not an HD or Wally World item.

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Thanks Sam.

If you are using cardboard tubes though some slightly-thinned (w/water) Elmer's filler is still your best bet. I tend to use Bondo spot putty for Blue Tube (to stay away from a water based product). For phenolic tubes I never fill, well I laminate with fiberglass, so that's filling.

SuperFil's application is really after you get to the glassing/epoxy stage as it is specifically designed to bond to that epoxy bases.

I recommend automotive glaze. Primer base is required for best adhesion when using glaze. Use this sequence: Prime, glaze, sand, prime, sand. Old credit cards, current credit cards you probably shouldn't be using, rewards program cards, even playing cards work well to apply glaze with precision and while minimizing over-application. When sanding glaze, use a numerically ascending sequence of grits e.g. 180, 220, 320 for a smooth finish. This method also minimizes the risk of damage or "rash" to underlying glassine or other smooth surface tubing layers.

Rocket guys call it spot putty, automotive industry predominantly refers to the most superficial layer of filler as glaze, which is often used on top of primary fillers (Bondo). There are a myriad of manufacturers to choose from for either. With thin-walled, flexible cardboard tubes, avoid primary fillers (Bondo) as these will require more intensive sanding for removal and introduce greater risk of burn-through, shrinkage, staining (depending on the type of paint you choose, if using as last layer/no primer overlay), frustration and fatigue.

dixontj93060 said:

Thanks Sam.

If you are using cardboard tubes though some slightly-thinned (w/water) Elmer's filler is still your best bet. I tend to use Bondo putty for Blue Tube (to stay away from a water based product). For phenolic tubes I never fill, well I laminate with fiberglass, so that's filling.

SuperFil's application is really after you get to the glassing/epoxy stage as it is specifically designed to bond to that epoxy bases.

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Thanks for setting me straight on the application Tim. I remembered you talking about Superfil in many build threads and when the OP mentioned epoxy I thought it worth bring up here. I've done exactly one glass cloth on cardboard layup, mostly as an exercise, and used two cans of Kilz to fill the weave ('cause that's what I had handy). The right tools for the right job make a big difference !

Then there's Rusto's filler primer... comes in a rattle can, and is available from Home Depot.

Besides Home Depot and Walmart, you can find a lot of useful rocket finishing material at automotive stores: Bondo, spot putty, other choices in spray paints, etc.

K'Tesh said:

Then there's Rusto's filler primer... comes in a rattle can, and is available from Home Depot.

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How many coats of filler/primer do you find you need? I have found that the grooves are a bit large to rely purely on the primer, but maybe I just never tried enough coats.

Many of us Old timers have found over the years for standard Craft tubes for LPR and MPR models. Fillers are unnecessary, expensive and time consuming.
Instead we use Cheap Grey Auto primer to fill both body tube spirals and balsa/basswood grain at the same time.

Generally it's applied in three heavy coats, allowing about 3-5 minutes between coats. after the third wet coat is applied the model is allowed to dry (Completely) using the sniff test to ensure all the solvents have outgassed. This can take from overnight to 3 days depending on the Weather,Temp and Humidity where the model was sprayed. Then dry sand with 240 grit sandpaper until the grain and seams disappear. If you hit wood or cardboard another 3 coats are applied and the process repeated. After the second 3 coat application sanding is done with dry 360grit sand paper to a babies butt smooth condition. Any thing finer is simply a waste of time as our Base color coat of paint will need a little tooth to add to the paints adhesion to the primer.
With this method and a bit of practice Glass smooth finishes can be obtained with just about any brand or type Rattle can spray paint.
This method sure cuts down on the down time waiting for "fillers" to set then sanding and priming anyway.

As for cost! I use the cheapest rattle can primer I can find. Currently Wal-Mart grey auto primer (does NOT have to be "High Build") @ 1.11 /12oz can. I usually get one or two standard LPR models or a MPR rocket for a single can.

If there is a down side to this method it is you will need some sort of spray booth or box with plastic tarps to control a bit of over-spray that occurs during the process.

K'Tesh said:

Then there's Rusto's filler primer... comes in a rattle can, and is available from Home Depot.

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+1 on this. It's all I use now.

One heavy coat of filler primer, sand with 220 or 320 so the glassine on the tube is showing in most spots. If there are any deep holes to fill, like spirals, I use spackling compound or joint compound since the fill doesn't have to have any structural strength. It sands away very easy with 220 or 320, leaving only a little in the filled spirals. A second coat of filler primer and sand that down to the glassine again, looking for any other spots that need filling. A final coat of filler primer and sand that smooth with 320 or 400, but this time, the glassine should not be showing through. Then I usually put a white base coat on using the $0.97 white rattle cans of Wal-Mart paint. If you do use the cheap Wal-Mart white for the base coat, let it sit at room temps for a week or more before you put any top coats on it.

Just a note here, I'm usually looking for a 15 ft. paint job so I only go through this process for the ones I want a better than usual paint job on.

mbecks said:

Hi, I don't usually buy rocket specific supplies because there hard to find where I live. My question is does anyone know of any good epoxy or something similar I could use to fill the body spirals ect. that can be purchased at like home depot or Walmart? I was almost thinking of just lightly painting my whole rocky with wood glue and then sanding it for painting.

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That is exactly what I do.
I first lay a little in the spirals and give it 2 or 3 coats, then sand.
After the MMT is in, I coat the inside of the tube too.
Helps prevent heat damage on frequently launched rockets and makes it stronger.
But it does take time, so if your in a hurry, go with the putty.

Duct tape works really well, comes in lots of colors and patterns, and doesn't require painting
Oh, and it only requires one coat!

This is a poor answer.

If a blemish Is detected with the naked eye it need some sort of filler and followed up with sanding. Period. Repeat if necessary.

If you can see a problem before finale paint, finale paint ain't gonna make it go away.

I love Superfil but it is overkill for spirals on paper tubes. Elmer's is the way to go for those IMO.

K'Tesh said:

Then there's Rusto's filler primer... comes in a rattle can, and is available from Home Depot.

Click to expand...

This is a poor answer.

If a blemish Is detected with the naked eye it needs some sort of filler and followed up with sanding. Period. Repeat if necessary.

If you can see a problem before finale paint, finale paint ain't gonna make it go away.

Think about it, what happens to paint when it is twisted or flexed?

Snap, crackle and "pop". That is what happens.

bradycros said:

This is a poor answer.

If a blemish Is detected with the naked eye it needs some sort of filler and followed up with sanding. Period. Repeat if necessary.

If you can see a problem before finale paint, finale paint ain't gonna make it go away.

Think about it, what happens to paint when it is twisted or flexed?

Snap, crackle and "pop". That is what happens.

Click to expand...

Uhh, whats the difference between primer and fillers? Primers are more flexible than fillers, and high build primers do the same job on smaller blemishes. I've had more filled spots pop on rockets than primered ones, unless it was a polypropylene nosecone without adhesive promoter.

bradycros said:

This is a poor answer.

If a blemish Is detected with the naked eye it needs some sort of filler and followed up with sanding. Period. Repeat if necessary.

If you can see a problem before finale paint, finale paint ain't gonna make it go away.

Think about it, what happens to paint when it is twisted or flexed?

Snap, crackle and "pop". That is what happens.

Click to expand...

Huh? High build primers work fine for grains and typical BT lines. I've never had one pop except maybe where there was severe landing damage. As someone noted, plastic cones are a different animal entirely. For that matter, I've never had fill'n'finish pop save maybe fillets on hard landings.

When it comes to finishing, I trust Micromeister. His builds are generally indistinguishable from plastic models.

Edit: Could be I misconstrued the quoted post. And I agree that the color coat won't hide imperfections.