Wood putty?

[Tbmx3]

Hi, I'm new to this site (just a few days) and fairly new to the hobby(a few months). Is it ok to use wood filler/putty around the fins for the crisp look? It's just so easy to work with. Not for structure in any way. Is there a weight concern with the above technique? I haven't noticed it mentioned on this site any where. Any advice would be useful, thanks
Brandon

 

[kuririn]

Perfectly fine. Some builders use Squadron putty, some use Elmer's Carpenter's Wood Filler (CWF). Just a matter of personal choice. Should be tons of threads if you do a search.

 

[Tbmx3]

Thanks

 

[Andrew_ASC]

I’m currently using Bob Smith’s epoxy, Elmer’s CWF, and testors plastic model glue to assembly a MPR build. I’m considering Bob Smith’s on the fins because it won’t warp as bad, but I may end up using Elmer’s anyways.

 

[Brainlord Mesomorph]

I paint the whole model in thinned Elmers CWF.

Fills in tube spirals, smooths fins and fillets.

 

[Andrew_ASC]

Elmer’s CWF used on fins on my first MPR build. No problems here.

 

[Andrew_ASC]

Here’s an example photo. I’m still new at this.

 

[Tbmx3]

Is there a specific ratio you guys mix it, also when you "paint" everything do you worry about contracting? With all the extra moisture

 

[neil_w]

Chris Michielssen (hcmbanjo on this forum) described his preferred ratios on his blog. If you search you should be able to find it. Generally, he uses a slightly thicker mix for filling tube spirals, and thinner for painting onto balsa. I followed his ratios when I was starting out and now just do it by feel. It's mostly filler; just a bit of water is needed to thin it out substantially.

The moisture content is an issue when filling balsa fins. Chris does one side at a time, and claims that coating the second side un-does the warp from doing the first side. I've had mixed results with that myself; I try to do both sides at once if possible, and stand the fin up on its root edge on a piece of tape to dry. That's not an issue for balsa nose cones, which are solid and won't warp.

BTW I'm not clear if you're talking about using the filler as grain and spiral filler, or as fillets on your fins. When you say "a crisp look" I'm not sure what that means. Can you clarify?

 

[Tbmx3]

Just using for fillets. When sanded, it makes it look so uniform. Like it's all one piece.

 

[kuririn]

You can use CWF as a smoothing fillet. Just be sure that the primary fillet underneath is glue. You can also use a clay or paste epoxy like milliput, a modeling putty like Squadron or Bondo. Epoxy is not sandable, there's a technique for getting smooth fillets involving denatured alcohol and masking tape dams. For low power most builders just use CWF.
Forgot to mention that you can get smooth fillets with wood glue by using your finger or a popsicle stick.

 

[Tbmx3]

Thanks for the tips guys!

 

[snrkl]

Just using for fillets. When sanded, it makes it look so uniform. Like it's all one piece.

With some practice you can lay wood glue fillets that are smoothed with a finger and end up smooth as a babies behind.

For LPR, I do fillets in two passes with Selly’s Aquadhere Exterior wood glue (AUSTRALIAN wood glue)

I’m standing next to my collections so here’s an example of a typical result for me, after 4-5 LPR rockets worth of practice.



Sometimes, if I’m too liberal with the amount of glue, I’ll get an air bubble, and that I might do a pass over with some wood filler.

 

[snrkl]

One other thing: get a dark or red wood filler. I bought a big tub of white thinking it would be more seamless, but instead it just makes it harder to see what you’re doing when sanding. Once I’ve finished this pot, I’ll be getting a mahogany red or some such...

 

[Tbmx3]

Yes I agree, the lighter filler is harder to see. That's some nice looking work you got there. I've been trying to hone my skills, I'll keep practicing!

 

[Andrew_ASC]

Nice fillets.

 

[solid_fuel]

I do thin layers of wood glue. And build up the fillet with many layers.
This is after a bunch of layers already.


Put a little bead from the bottle


Smooth with finger tip.


Repeat until thickness desired is achieved. These are pretty much done to my liking.

 

[jqavins]

There's a DAP product I've been using for a good while with good results. It's light weight spackle, and it's actually a foam. Spreads like well whipped frostimg, dries paintable and sandable, and weighs almost nothing. I use it for cosmetic fillets and filler alike.

The last time I went to buy some, I found a 3M product that's similar but has primer mixed in. So I picked it up and gave it a try, and after one build I love it. Note, this build had spirals that didn'tneed filling and plywood fins, so this filler candidate still needs a good deal of testing.

Oh, and...

Welcome to the forum, welcome to the hoby, and keep asking those questions.

 

[neil_w]

The last time I went to buy some, I found a 3M product that's similar but has primer mixed in. So I picked it up and gave it a try, and after one build I love it. Note, this build had spirals that didn'tneed filling and plywood fins, so this filler candidate still needs a good deal of testing.

Hey, don't go thinking you can drop a line like that without telling us the name of the product...

 

[jqavins]

I tried to post a picture of the product, but I'm having trouble with either the new picture inclusion or with Google drive, and I was too tired to figure it out. I should have thought to include the name, and now the product is in my hotel room while I'm at work. It's something simple and self descriptive like "Patch Plus Primer". It is from 3M, and has the same "3X" trademark on it as their sandpaper.

For grain filler on the plywood I worked it in with a credit card then sanded lightly before separating the fins from their sheet; it filled so well that I had a little trouble finding the laser curfs, but only a little. For fillets, I just pus some on and smoothed it with a finger like pretty much anything else.

 

[neil_w]

Ah, here it is. Maybe I'll get a tub and experiment. I have some other lightweight spackle that I haven't tried to use for rockets yet; it's *extremely* light and pretty easy to work with, no smell and water cleanup. I like the idea.

 

[lakeroadster]

Titebond Quick and Thick works great for fillets..... It's quick and thick..

 

[jqavins]

Yep, that's the new stuff

The other stuff I've used before is this DAP product. It's so light that a new pint container feels empty when you pick it up. The package says it's ready to paint in minutes, which may be true if you're using latex paint, but read on; it needs 24 hours if you intend to sand or use any paint except latex. Give it the time and it works really well. If the 3M doesn't hold up well to further testing, I'll be perfectly happy going back to this.

 

[Andrew_ASC]

Titebond Quick and Thick works great for fillets..... It's quick and thick..
View attachment 359036

That’s the stuff I wish I had during my Conquest Build. Man Elmer’s CWF works but is a pain. I also used Extreme Power CA thick on the tail to cardboard but it dries instant.

 

[T-Rex]

CWF works great for its intended purpose, filling grain. I have never tried to use it for fillets, though I have noticed that it will fill a rounded leading edge to square again.
I generally use glue smoothed with a finger for fillets, first pass is wood glue, then subsequent passes of Thick & Quick.

 

[Rainmaker]

I use it for cosmetic fillets. I thin it slightly so it's the consistency of peanut butter, spread it on with a popsicle stick. I don't even try to make it pretty when applying. Sands super easy with a short piece of PVC.