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Balsa/Cardboard to Plastic?

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Johnny1Eye

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What do you use to glue this stuff together? Directions say to use regular plastic model cement. I seem to remember having problems with that? I am speaking of the Estes Canadian Arrow. Although I do have other(much larger) rockets with similar issues. I would hate to see it come apart as it leaves the pad on an F24 or something....

-Jon
 

MarkII

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Epoxy works most of the time (there is some that is formulated especially for plastics). You should roughen up the plastic in the area that is to be bonded in order to give the adhesive more surface area to grab onto. Gorilla makes a white version of their polyurethane-based glue that may work, too (Give it time to cure.) I haven't used it for bonding plastics yet, but I can attest that it gets firm and unbelievably sticky as it cures after it has been applied to a slightly dampened surface. (Be aware that it also swells up, too.) Wear gloves, because you don't want to get any of this stuff on your hands. (You'll never get it off.) Once it has fully cured, the white Gorilla glue can be sanded, so any glue that has swelled up and is visible or unsightly can be removed. Also use disposable applicators for it, because nothing that I know of dissolves this stuff once it has cured.

MarkII
 

jadebox

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What do you use to glue this stuff together? Directions say to use regular plastic model cement. I seem to remember having problems with that? I am speaking of the Estes Canadian Arrow. Although I do have other(much larger) rockets with similar issues. I would hate to see it come apart as it leaves the pad on an F24 or something....a
On a larger rocket, I bolted a piece of wood to each side of the root edge of each plastic (Lexan) fin and used epoxy to glue the wood to the body tube.

I haven't tried it yet, but for a smaller rocket, I'm going to stick a thin strip cut from self-adhesive label paper to each side of the root edge of the thin plastic fins. They are going to be glued between tubes attached to the main body tube, so I think this work.

You could try something similar for gluing a plastic fin straight to a body tube. Run a little plastic cement or CA along the root edge of the plastic fin and glue it in place. Once it dries, add a fillet of white glue along the label paper to glue it to the body tube. As I said, I haven't tried this yet, so you might want to test the idea with some scraps of material. Also, it would leave a visible ridge where the fillet is, so it might work better with "through-the-wall" mounting where the fillet is hidden inside the body tube.

-- Roger
 

kjohnson

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What do you use to glue this stuff together? Directions say to use regular plastic model cement. I seem to remember having problems with that? I am speaking of the Estes Canadian Arrow. Although I do have other(much larger) rockets with similar issues. I would hate to see it come apart as it leaves the pad on an F24 or something....

-Jon
If you are going to use tube type plastic cement to bond a plastic part to a body tube, you need to use a two step process.

Step 1- Coat the cardboard area with the cement so that the body tube is impregnated with the cement. Let that dry.

Step 2- Put cement where the plastic is going to go and then put the parts together. For something like the Canadian Arrow where you are gluing a boat tail to the tube, use a twisting motion to spread the glue around as you put the parts together.

I had an old large sized R2D2 model that used this technique to glue the legs on the tube and they never came off- even after a few very hard landings.

These days I prefer to use CyA for that sort of stuff, usually medium thickness.

kj
 

Johnny1Eye

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Step 1- Coat the cardboard area with the cement so that the body tube is impregnated with the cement. Let that dry.

Step 2- Put cement where the plastic is going to go and then put the parts together. For something like the Canadian Arrow where you are gluing a boat tail to the tube, use a twisting motion to spread the glue around as you put the parts together.

I had an old large sized R2D2 model that used this technique to glue the legs on the tube and they never came off- even after a few very hard landings.

These days I prefer to use CyA for that sort of stuff, usually medium thickness.


I also have an old large sized R2-D2 sitting in my closet, and an X-wing fighter. Thats one of the reasons I asked.

CA works for good for plastic? What about the "maxi-cure" type CA (it's the thicker stuff)? gluing plastic to anything but plastic seems to make me nervous. I normally use Epoxy for pretty much everything (even LPR). It doesn't seem to work well with plastic. I like my rockets to be able to take some abuse, smaller fields= smaller chutes= not so soft landings.

I've used weldbond on several rockets with good results .

I used it exclusivly on a maxi honest john since there was alot of plastic glueing...still going strong.
I'll have to check that out, I always thought it was just elmer's type stuff under a diff. name.
 
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MarkII

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BSI makes a version of CA called IC-2000 that contains carbon rubber, which provides it with shock and impact resistance. IC-2000 is said to form a tougher, more resilient bond than any other CA, so it might work well for you. The carbon component give it a black color, though. BSI also makes a product called Insta Flex +, which is "rubber toughened" like IC-2000 but without the carbon component. It is clear when cured. These products may work in your situation. Also, on the subject of CA, when I have used BSI Insta-Set to flash-cure BSI Maxi Cure, the CA takes on a different character than when it is air-cured. It becomes extremely hard and tough and it is almost crystal clear, like acrylic. (I have used this effect to create fin fillets on occasion.) This may also work for you.

MarkII
 

exprditer789

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I would use a ca or epoxy but if you use ca give it a really good fillet with wood glue or epoxy.But give it a really good fillet no matter what you do. Alex
 

NjCo

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For something like the Canadian Arrow where you are gluing a boat tail to the tube, use a twisting motion to spread the glue around as you put the parts together.

These days I prefer to use CyA for that sort of stuff, usually medium thickness.
kj
Using plastic cement with the twisting application has always worked for me in instances like this. I have never had a joint fail in these types of situations. But these types of joints aren't prone to a lot of stress.

I'm always cautious about using CA since it is a fairly brittle bond. It's not a very long term solution for parts with will get a lot of stress like fins. The CA with the carbon additive or some other material that allows some flex does sound enticing though. CA is also not a very good adhesive in my experience when it comes to styrene on styrene bonds. The fin attachment on the Estes D-Region Tomahawk and the rotor/nose cone attachment on the Estes Cosmic Cobra are two examples that seem to fail a lot. For these types of applications I always go with a methylene chloride bonding adhesive like ProWeld. That's the brand I use but there are many others.

This question caught my attention though because I am also in need of a styrene/balsa bonding agent. But in my case the two parts are not matched very well, unlike something like a fin being glued to a body tube or something similar. I'm building an Estes Interceptor right now and the styrene pods are glued to the balsa wings. The attachment isn't a very snug fit however. Far from it in fact. I might go with epoxy for this but the expanding Gorilla glue might also be a good option since the inside of the pod is empty and will provide some room for expansion and help hold the pod onto the wing.
 

Micromeister

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What do you use to glue this stuff together? Directions say to use regular plastic model cement. I seem to remember having problems with that? I am speaking of the Estes Canadian Arrow. Although I do have other(much larger) rockets with similar issues. I would hate to see it come apart as it leaves the pad on an F24 or something....

-Jon
Jon:
May I suggest a download of Tech-tip 017, Working with plastics from the library section of narhams.org website. it may help give you some insight as to things you need to know about different plastic construction methods.
Hope this helps.
 

BEC

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If you can find it, Wilhold RC 56 (but I don't think it's made any more). Alternatively , Pacer formula 560. Both are sold for gluing plastic parts to wood RC models (specifically canopies). It looks like Elmers but has a different odor. It produces a clear, slightly flexible bond which would be great for body tube-to-fin can type joints, or the pods on the Interceptor. Thick CA would work, but as noted by others the joint is fairly brittle.

I like that two-step approach using a plastic cement - it sounds like it's worth a try next time I have such a joint to do.
 
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