Help! What Dissolves "Resin"?

[sequoiaranger]

I have a "Planet Models" He-119 that may well be my next whif project.  It is a "resin" kit, and that seems to mean that I must use SuperGlue or something similar to weld it together. I would rather not.

I would prefer to have available some kind of "solvent" glue that would, like styrene cement to styrene, melt the margins of the two parts so they would weld to each other and solidify.

I have tried dissolving a small sprue piece of the "resin" in "lacquer thinner", and it was impervious.

I would THINK that there is something out there that dissolves or "melts" this resin.

ANY CLUES OUT THERE??

[Hobbes]

Why not use superglue? It's quite nice to work with, and gives a very strong bond.

[Ed S]

I don't think that there is anything available which can dissolve resin that you could safely keep in your house.  There may be some serious industrial strength acids that could do it.

So, basically, resin models need to be assembled with CA (superglue) or epoxy.  The 5-minute clear epoxies work pretty well and give you time to get parts aligned while it cures, but it also means that you have to clamp or hold the parts steady for the 3-5 minutes it takes to solidify.  Then you need to give it a least 12 hours to reach full cure.

Ed

[Brian da Basher]

I use CA almost exclusively now and I just love how quickly it bonds yet still leaves you a few seconds to position parts. While I don't build resin kits (too pricey), I've read that to attach larger, heavier resin parts the best option is to drill out small holes and insert a length of brass rod for added strength, securing everything with CA.

I hope this helps and I'm really looking forward to seeing your He-119!

Brian da Basher

[frank2056]

Some resins will soften with acetone, but they won't melt - they'll just be wrecked. If you don't like CA (I don't) you can use epoxy or a strong cement like Scotch Super Strength Adhesive, which is like the old Duco cement, only stronger.

[sequoiaranger]

Thanks, all, for the tips.

I will probably use CA glue with some sideways-drilled-in supports to strengthen the bond. I know that on the two fuselage halves of my He-119, there is a slight bow that I can bond with super-glue, but I worry that some sideways force "dropping it", maybe, can split the bond. CA is extremely strong in ONE direction, but is susceptible to side forces that will split the bond. That's why I would prefer "fusing" by melting.

I may use CA glue and epoxy with clamps for the big parts, then just CA or "Gators' Grip" for small parts.

This project is probably weeks away; I am just preparing at the present.

[NARSES2]

I build a lot of resin kits and you will be suprised at just how strong simple but joints can be with CA, very seldom do I feel the need for pinning (much more likely with butt joints on ltd editition IM kits) For bigger kits I use 5 min epoxy for the larger parts. Use medium strength and you should not have a "time problem"

Re Gator glue. Whilst it is excellent and has many varied uses, attaching a lot of resin parts is not really one of them. If you are gluing flat contact surfaces together then it's fine, it takes to long to dry for some uses unless you can find a method to suuport the parts without slipping. If using Gator I coat both surfaces, leave a little and then use almost as a contact adhesive. For attaching brass and canopies it's brilliant stuff

Chris

[TsrJoe]

through both hobby and industry experience, offhand i cant think of any readily avaliable resin 'solvent' to efficiently bond or 'fuse' the parts in a similar way to that of styrene based plastics

id agree with the previous posts using a cyano 'superglue' to bond the parts, possibly one of the longer setting ones for larger components with tape or clamps (or even 'accelerator' to hold firmly whilst curing?) normal cheap ca. works too, altho over a longer term iv found it a false economy

another glue suitable would be a 2 part 'fast setting epoxy, altho this can be frustrating and messy to use on occasion (from experience) with a variable 'cure' time.

most modern urethane based resins (as well as the older epoxy types) will soften when immersed over time in a strong solvent (eg. acetone, dcm., thf. or mek. but i would not in any way reccommend it as id think this would be more health nasty route than the resin dust itself!)

cheers, joe

[Mossie]

We used to a solvent called tetrahydrofuran to dissolve polyurethanes at one place I worked.  It's a very strong solvent, highly flamable & has strong narcotic effects if inhaled.  I can attest to this, some fellas pulled the top off a 45 gallon drum while I was stood next to it, I nearly hit the floor.

I don't think you'd get hold of this stuff unless you had a supply at work & I would say that it's too dangerous to use at home.  It'll dissolve any plastic or rubber it comes into contact with very quickly, a minor spill a mate had left some very gooey electrical flexes.  You could maybe get away with a tiny bottle full, no more than 50ml, but I wouldn't reccomend it.

[sequoiaranger]

TsrJoe, NARSES2, and Mossie, Thanks.

>We used to a solvent called tetrahydrofuran to dissolve polyurethanes at one place I worked.<

I'm not sure what the base resin material is of my He-119, though I suspect it is polyurethane. I have had many of the old epoxy resins (bubbles and all) from the '70's and the He-119 doesn't look like that. The Planet Models He-119 is a relatively "new" product (that is less than twenty years old), so it is most likely a "modern" material.

>It's a very strong solvent, highly flammable & has strong narcotic effects if inhaled. <

That sounds like Revell Type "S" to me (*see photo--it cost a whole 15 cents in the early 60's)! Maybe I can order a small bottle and, to be on the safe side, ask them to put some "oil of mustard" in it! 

Say, can we be inducted into the "Mile-High Club" if we construct a model while in an airplane???

[jcf]

Hi Craig,
personally I like using fast-set epoxy thickened with colloidal silica and bulked-up with micro-balloons, doesn't 'sag' off the joint and acts as filler. Add the thickening/bulking agents to the pre-measured epoxy resin and then add the hardener and mix.

Evidently tetrahydrofuran is the primary ingredient in PVC cement, used for piping etc., so perhaps you could try some of that? Being aware that It does pong something awful and will make your head spin.

Jon

[sequoiaranger]

I have micro-balloons left over from some failed resin projects, but I don't have any "Colloidal Silica". Where does one find such stuff, and is it "powdered" and possibly dangerous to inhale as dust? Or is it truly "colloidal" and in suspension of some medium?

[jcf]

Hi Craig,
any marine/boat supply that carries epoxies should have the silica, look for silica thickener.
It is also known as fumed silica and is a powder (don't inhale!) that becomes colloidal when mixed into the resin.
The resulting thickened glue becomes thixotropic, meaning that it will stick to a vertical surface and not run.

Do some test mixing before committing to a project as when adding the silica you can go from still runny to a stiff putty in a heartbeat, ditto the micro-balloons. 

Another option is System 3 Silvertip GelMagic, a two-part epoxy that changes state from liquid to thixotropic paste when mixed.
However it is not quick cure, you'd have to leave your parts clamped overnight.

System 3 sell a trial kit that includes a variety of their products for $29.00 (post paid continental US)... more than enough material for numerous modeling projects. 
https://www.systemthree.com/trial_kits.asp

Jon

[HOG]

"I know that on the two fuselage halves of my He-119, there is a slight bow that I can bond with super-glue, but I worry that some sideways force "dropping it", maybe, can split the bond. CA is extremely strong in ONE direction, but is susceptible to side forces that will split the bond. That's why I would prefer "fusing" by melting. "

Hi Craig,
           Some `cheats` that may help.
For small directional alignment problems in resin, try tapeing/tieing the part onto a straight board and steaming over a kettle and immersing into cold water. This, I have found, often cures small flaws and bows. Also have used a hair dryer and a hot air paint remover with success depending on part size.
For stronger superglue joints drill small holes in both sides to be joined and prefill these with superglue and let set. Join in normal way and the glue bonds the `holed` glue with itself making a sort of reinforced join. This helps with the fractional /directional failure of most superglues.
If you don`t want to pin the joins, attacking the resin with grinding wheels to leave grooves dents etc and glue with epoxy resin is a more `butch` job than the superglued holes above.
I`ve worked with resins for about 25 years and have yet to find a solvent that works when its fully cured but I hope these help.
Cheers 
G

[sequoiaranger]

>For small directional alignment problems in resin, try tapeing/tieing the part onto a straight board and steaming over a kettle and immersing into cold water. This, I have found, often cures small flaws and bows. Also have used a hair dryer and a hot air paint remover with success depending on part size.

For stronger superglue joints drill small holes in both sides to be joined and prefill these with superglue and let set. Join in normal way and the glue bonds the `holed` glue with itself making a sort of reinforced join. This helps with the fractional /directional failure of most superglues. If you don`t want to pin the joints.... <

Thanks. I will most likely "pin" the fuselage halves with steel guide pins and superglue the thing together. The hot water/cold water trick might work, too. I hesitate to do it as I only have ONE model (I usually have at LEAST two of anything I might want to whif) to work with. At least the model is still manufactured. If I screw up, presumably I can just buy a new one, though they are expensive!

*LOVE* that word "Thixotropic".