Putty as a joiner?

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Digger1

Putty as a joiner?

Post by Digger1 »

Can I use putty alone to join two plastic surfaces?

I want to try to get a seamless joint between the bridge and the B&C decks of the PL TOS Enterprise and the only way I can think to do that is put putty down and then press the bridge in place.
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Post by big-dog »

No way, putty has no strength, it's a filler. Why not use Testors liquid, the stuff in the bottle? Apply like contact cement. Press the 2 parts together, it may only stick where it touches, but let it dry, then it'll be strong.

Unless you want to use 2-part Bondo, that'll hold. That is 2-part Bondo body filler, not the putty.
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Post by Digger1 »

But does not putty contain a little bit of that chemical that can attack plastic if too much is used? Seems to me that there needs to be a little of that in there to slightly melt the plastic to give the putty something to hold on to. That being true, shouldn't putty be able to join two plastic parts?

Has anyone tried it?

Oh, for the record, I have been trying the tenax route with limited success. What I do is; apply the bridge dome to the saucer and them put on the biggest, strongest clamp I have and then let some tenax run into the seam hoping there'll be no visible seam left. Doesn't really work that well for me.

When I apply the liquid cement before I apply the part, liquefied plastic oozes out of the joint making an unsightly mess that doesn't seem to want to cure and if/when it does cure, I won't have the dexterity to clean up the seam.
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Post by Chacal »

Putty is grained, so it WILL crack and crumble under any real stress. Because of that, it CAN'T be used as adhesive. In you case, however, you can "double up". Use epoxy adhesive (I think its slow setting will be best than CA's fast setting) on the center of the gluing area, and a bit of putty around the edges.
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Post by Romulan Spy »

I haven't tried this myself, but here's my thought. That bridge dome fits pretty tightly to the main saucer, so a super-strong glue joint really isn't needed. Why not mix Bondo with plain liquid cement? Make a thin goopy mixture, slather it on, then press the dome into place. While the putty-glue mix is still wet, clean up the excess and smooth out the joint with a Q-tip soaked in acetone. After it dries use a little Mr. Surfacer to finish the joint.

Just my $0.02.
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Post by Digger1 »

Good thinking with that mix of putty and cement, Romulan!

Which should I use, the thicker tube kind or the liquid tenax kind?

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Post by Romulan Spy »

I was thinking plain old fashioned Testors liquid cement, but the Tenax should do the same thing.
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Post by Digger1 »

Romulan Spy wrote:I was thinking plain old fashioned Testors liquid cement, but the Tenax should do the same thing.
same thing. Apples and apples.
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Post by Sparky »

If the putty is Aves epoxy putty, it will provide a very strong joint. Rough up the surface and or put pins in (make sure their surface is ruffed up too).

<a href="http://www.kc6sye.com/images/images_03_ ... attach.jpg" target="_blank">I used these mini hex nut screws (they're from the hobby shop) to provide threads for the aves to grip</a>.
<a href="http://www.kc6sye.com/images/images_05_ ... eg_bnd.jpg" target="_blank">Then I mushed the joint together and smoothed the aves with water and metal sculpting tools.</a>

The joint seems really strong but the true test will be to transport it to a wonderfest and back.
Last edited by Sparky on Thu Dec 08, 2005 6:00 pm, edited 1 time in total.
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Post by en'til Zog »

Plunk the bridge in place, then apply Tenax from the INSIDE of the other part. Let it 'wick' up into the joint, then apply pressure. Not a lot of pressure, just enough so the bridge settles down a bit. Then let 'set'. If there's still a join visible, paint it a few times to fill it in.

Works for me! :D
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Post by TER-OR »

Yes, Epoxy Putty will act as an adhesive. For the best joint with styrene you should cement some bits of plastic to act as studs for better joinery. At the very least cut grooves in the surfaces. A smooth surface isn't good for epoxy.
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Post by Owen E Oulton »

There's actually a real simple solution. The top ov the B/C Deck is rounded in the area of the opening, while the bottom of the Bridge Deck is flat. Take a sanding stick or file and very carefullt flatten out the area surrounding the mounting hole - be careful that you dont flatten out the whole top, just an area a couple of mm wide around the hole - and the Bridge Deck will fit in place with no gap at all. A drop of liquid cement, and the seam disappears.
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Post by Lt. Z0mBe »

Sparky wrote:If the putty is Aves epoxy putty, it will provide a very strong joint. Rough up the surface and or put pins in (make sure their surface is ruffed up too).

<a href="http://www.kc6sye.com/images/images_03_ ... attach.jpg" target="_blank">I used these mini hex nut screws (they're from the hobby shop) to provide threads for the aves to grip</a>.
<a href="http://www.kc6sye.com/images/images_05_ ... eg_bnd.jpg" target="_blank">Then I mushed the joint together and smoothed the aves with water and metal sculpting tools.</a>

The joint seems really strong but the true test will be to transport it to a wonderfest and back.
"Behold, he that joineth the pieces of his home, his hearth, his ass, his neighbor's ass, his model, and his wounds with Bondo and Ketones and Xylene shall pass from this earth with broken home, broken hearth, broken neighbor's ass, broken wounds, and stenchful sores upon his hands and feet. For Bondo, you see, is for hiding small flaws. Aves will mend all homes, hearths, asses, models, wounds, and more asses. Know yee this day Aves, who cleanseth the sculptors' and builders creations of all iniquities, and bondeth them forever and ever, amen. "

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Post by Digger1 »

I tried it on the Romulan Warbird neck just now. It appears to be holding. I'll sand it down and post a pic tomorrow when it's dry and smooth.
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Post by big-dog »

I noticed from a prior post you said you've been using the biggest, strongest clamp you have and then applying the Tenax, or Ambroid, they're the same. That won't work. The liquid cements sneak into the joint by capillary action. If the joint is too tight there's no room for the solvent to go. You'll get a tiny bead of adhesion around the edges, nothing else. Leave the clamp just tight enough to keep the bits aligned, then apply the adhesive, I like micro brushes, I can't find a ruling pen, THEN tighten down the clamp.
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Post by Digger1 »

Didn't work.

The slightest bump caused it to dislodge and crack.

Is there a way to mix a little glue into the putty to create a more permanent bond?
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Post by Sparky »

You're aves came loose? You need to scuff up the area before applying it. Give it a surface to grip to, make sure the putty is tacky even a little wet so it can get into the surface. Even if you use 1200 grit to give the surface some texture this should get it to bond.
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Post by Digger1 »

aves?

Nope. Bondo.
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