repair for my VF-19

[jemC]

I bought a 2nd hand VF-19 and the arms broke at the plastic portion near the joints. 

Can I use this to repair the plastic with Permatex 84145 Permapoxy Black Plastic Weld? https://www.ebay.com/c/26014850560?

I do not have the Devcon Plastic Welder in my country and US does not ship here.

• Devcon 22045 Plastic Welder

 

 

 

[Darth Mingus]

Can you post pictures of the break?  depending on how it broke, glue may not be sufficient, you may need to drill and insert rods to add strength.

[jemC]

Right now, I don't have the toy with me but I'll post over the weekend to show the break

[Froy]

The old Yamato explodium.

Basically the upper arm part bellow the part that slides down for battroid mode just disintegrate. Happened to mine.

I just used some crazy glue.

[jemC]

3 minutes ago, Froy said:

The old Yamato explodium.

Basically the upper arm part bellow the part that slides down for battroid mode just disintegrate. Happened to mine.

I just used some crazy glue.

Hi Froy,

Is crazy glue some kind of super glue?

 

[Anasazi37]

28 minutes ago, jemC said:

Hi Froy,

Is crazy glue some kind of super glue?

 

https://en.wikipedia.org/wiki/Cyanoacrylate

All essentially the same stuff

[jemC]

Hi all, 

This is the breakage 

 

As you can see, the breakage is on both hands. Just below the shoulder joint and at the hinge portion.

 

 

With the hand removed, on the side view, both hands have the plastic pieces broken. One from the top and the other from the bottom.

 

The broken pieces are clean breaks. This caused the arms unable to remain on the body in fighter mode

 

 

This is where the broken pieces were supposed to be attached to the main body.

 

A closer look at how the breakage looks like.

 

Thus, I need some help.

1. From the above, is it recommended to just use Zap-a-Gap to paste them back or is it recommended to have additional internal support stabilizers before applying the super glue?

2. Should I use super glue or those epoxy glue like Permatex 84145 Permapoxy Black Plastic Weld? https://www.ebay.com/c/26014850560?

 

[Sanity is Optional]

Oof, that's not a good break.

High load area, and not a lot of space to glue it back together or pin reinforce it.

If you do glue it back together, I'd also glue the metal peg into the opposite side to help carry part of the load.

[jemC]

21 minutes ago, Sanity is Optional said:

 

If you do glue it back together, I'd also glue the metal peg into the opposite side to help carry part of the load.

Could you help to explain a little more as to which opposite side?

Also, I just had a look again, a metal insert might not be possible. the area seemed too small. 

[Sanity is Optional]

So you see the pin that's already there, that goes from one side of the broken part to the other?

Glue it in on the other end, it'll help distribute the force across both sides, rather than just the side the pin's attached to.

As a mechanical engineer, the reason those both failed in the exact same way is that the force from the arm is concentrated on only one side of the hinge, specifically at the squared interior corner where it broke. There's a reason why putting a small radius in is a good idea.

[jemC]

13 minutes ago, Sanity is Optional said:

So you see the pin that's already there, that goes from one side of the broken part to the other?

Glue it in on the other end, it'll help distribute the force across both sides, rather than just the side the pin's attached to.

As a mechanical engineer, the reason those both failed in the exact same way is that the force from the arm is concentrated on only one side of the hinge, specifically at the squared interior corner where it broke. There's a reason why putting a small radius in is a good idea.

I see what you mean. 

So, I'll just glue on the breakage point as well as the other side of the pin. 

It's something I've never thought of. Good point. 

Any idea if Zap A Gap works for this?

Will it causes the white fogging issues on these plastic parts?

[Sanity is Optional]

I'd expect anything you do to be more functional than aesthetic.

Personally I'd search for a good 3M A+B epoxy, one that will work with both plastic and metal, and has a low viscosity with a n appropriate set time (5-30min range?).

Might want a higher viscosity if there's a large gap between the metal pin and the hole, and if so check what the maximum bond thickness is.

 

Or just use some crazy glue and see if it falls apart again. I spend far too long researching appropriate glues for things at work...

 

[edit] This stuff seems like it'd do the job: https://www.mcmaster.com/74765A22/

Clear superglue, begins curing in 15sec, and full harden in 24 hours. Low viscosity, high maximum bond thickness. Bonds to most plastics and metals.

Edited October 10, 2020 by Sanity is Optional

[jemC]

11 minutes ago, Sanity is Optional said:

I'd expect anything you do to be more functional than aesthetic.

Personally I'd search for a good 3M A+B epoxy, one that will work with both plastic and metal, and has a low viscosity with a n appropriate set time (5-30min range?).

Might want a higher viscosity if there's a large gap between the metal pin and the hole, and if so check what the maximum bond thickness is.

 

Or just use some crazy glue and see if it falls apart again. I spend far too long researching appropriate glues for things at work...

 

[edit] This stuff seems like it'd do the job: https://www.mcmaster.com/74765A22/

Clear superglue, begins curing in 15sec, and full harden in 24 hours. Low viscosity, high maximum bond thickness. Bonds to most plastics and metals.

Thanks mate. 

I'll have a look at both 3M A+B epoxy and mcmaster. 

 

 

 

[slide]

On 10/10/2020 at 1:24 AM, jemC said:

Thanks mate. 

I'll have a look at both 3M A+B epoxy and mcmaster. 

From a modeler's perspective:

I would drill 2 holes and pin each broken piece in place with some brass rod addition to even the epoxy.

I suggest you DEFINITELY pin it if you're going to try CA of any kind. Zap-a-gap should work as well as any other CA [crazy glue]. 

 

 

Pinning it may be time/trouble spent, but those breaks look like they could do with the extra re-enforcement, and I would expect a CA repair-job to crack under any appreciable stress.

Good luck with your fix!

[jemC]

9 hours ago, slide said:

From a modeler's perspective:

I would drill 2 holes and pin each broken piece in place with some brass rod addition to even the epoxy.

I suggest you DEFINITELY pin it if you're going to try CA of any kind. Zap-a-gap should work as well as any other CA [crazy glue]. 

 

 

Pinning it may be time/trouble spent, but those breaks look like they could do with the extra re-enforcement, and I would expect a CA repair-job to crack under any appreciable stress.

Good luck with your fix!

Hi Slide

Can I assume that you would recommend a pin to be drilled in the middle here?

 

 

The breakage is in an slanted position and when the shiny metal pin in the picture goes through the hole in the arm, it would be in an awkward position to have the additional pin. 

 

Any solution for that?

 

[slide]

On 10/11/2020 at 10:20 PM, jemC said:

 

Any solution for that?

 

I would use 1, maybe 2 pins if you have the physical space at a right angle to the part itself. normally I would recommend 90^o to the break, but that'd make this even more complex/difficult 

something like this:

*this is dependent on the internal structure of the joint, of which I'm completely unaware, but if it's just a plastic-only part of the joint, I would use epoxy and 2 pins [because I'm type-A, and using two will give you extra stability to the repair] in the yellow locations above. 

this will keep the pins away from any actual moving portion or negative spaces required for mobility.

if you do not have a vice and some kind of drill-press, then doing it this way will be extremely difficult to get correct and not slip and mar/break the joint up even worse

 

Order of operations in my head: 

1. A LIGHT scuffing with some sandpaper to the break itself will help give the epoxy something [texture] to bite onto and will hold better. Epoxy the broken joint-flange into place, making sure it's as square and tight as possible. let the epoxy dry. *note* you can stop at this point and test-out the joint's function/strength if you like. maybe you won't even need to pin it, but I suspect you will.
2. I would then put the joint in a vice, and mark-out then drill the two pin-holes. I don't know if going all the way through is necessary, but I'd sink the pins at least half-way into the joint. The more 'meat' of the broken flange you can use, the better IMO
3. Trim the pins so they are just a little bit countersunk into their holes [ever so slightly recessed] then drench the pins in epoxy, place them into the joint, and wipe off the excess. This should have the benefit of sealing the pins in all in one fell swoop.
4. now you can fill/sand/paint if you feel you need to.

Once you've reached step 2, feel free to modify the angle of your pins if you like, perhaps perpendicular to the break itself would be best from a mechanical strength standpoint... but I'm not an engineer, I just play one in my hobbyroom!

 

WARNING: doing it my way will further damage the part before you make it better!! and stands a reasonable chance of outright failure!

I'm fully aware that doing it my way is NOT going to leave it pretty without additional work [filling, sanding, painting] and you need to know that too, before you start

But as a model-builder, that's how my brain immediately tackled the problem.

Shy of machining yourself a new piece, this is the most sturdy/long-lasting repair I can think to make.

My method may prove to be overkill, but overkill is under-rated and if you play with her at all, I would not trust an epoxy-only bond for any appreciable force on a repair surface-area of that size. 

 

Hope this either helps, or inspires a better/simpler solution. I like to overthink things like this so TIFWIW

Good luck!

Edited October 13, 2020 by slide

[jemC]

6 hours ago, slide said:

I would use 1, maybe 2 pins if you have the physical space at a right angle to the part itself. normally I would recommend 90^o to the break, but that'd make this even more complex/difficult 

something like this:

*this is dependent on the internal structure of the joint, of which I'm completely unaware, but if it's just a plastic-only part of the joint, I would use epoxy and 2 pins [because I'm type-A, and using two will give you extra stability to the repair] in the yellow locations above. 

this will keep the pins away from any actual moving portion or negative spaces required for mobility.

if you do not have a vice and some kind of drill-press, then doing it this way will be extremely difficult to get correct and not slip and mar/break the joint up even worse

 

Order of operations in my head: 

1. A LIGHT scuffing with some sandpaper to the break itself will help give the epoxy something [texture] to bite onto and will hold better. Epoxy the broken joint-flange into place, making sure it's as square and tight as possible. let the epoxy dry. *note* you can stop at this point and test-out the joint's function/strength if you like. maybe you won't even need to pin it, but I suspect you will.
2. I would then put the joint in a vice, and mark-out then drill the two pin-holes. I don't know if going all the way through is necessary, but I'd sink the pins at least half-way into the joint. The more 'meat' of the broken flange you can use, the better IMO
3. Trim the pins so they are just a little bit countersunk into their holes [ever so slightly recessed] then drench the pins in epoxy, place them into the joint, and wipe off the excess. This should have the benefit of sealing the pins in all in one fell swoop.
4. now you can fill/sand/paint if you feel you need to.

Once you've reached step 2, feel free to modify the angle of your pins if you like, perhaps perpendicular to the break itself would be best from a mechanical strength standpoint... but I'm not an engineer, I just play one in my hobbyroom!

 

WARNING: doing it my way will further damage the part before you make it better!! and stands a reasonable chance of outright failure!

I'm fully aware that doing it my way is NOT going to leave it pretty without additional work [filling, sanding, painting] and you need to know that too, before you start

But as a model-builder, that's how my brain immediately tackled the problem.

Shy of machining yourself a new piece, this is the most sturdy/long-lasting repair I can think to make.

My method may prove to be overkill, but overkill is under-rated and if you play with her at all, I would not trust an epoxy-only bond for any appreciable force on a repair surface-area of that size. 

 

Hope this either helps, or inspires a better/simpler solution. I like to overthink things like this so TIFWIW

Good luck!

wow! Thanks slide for the detailed explanation. 

Everything you said makes complete sense and well noted on the warning. 

I'll seriously consider your suggestions and once I've some free time, I will look to work on it.

[no3Ljm]

That's a cool instructions. I'm quoting most of it in the Macross Maintenance thread if that's ok.

 

[nightmareB4macross]

On 10/13/2020 at 9:01 PM, jemC said:

wow! Thanks slide for the detailed explanation. 

Everything you said makes complete sense and well noted on the warning. 

I'll seriously consider your suggestions and once I've some free time, I will look to work on it.

Did you have success with your repairs?

[dur]

I will second the person who said its worth your time to drill and pin.  I have repaired teeny tiny wrist joints on 1/25 Joy Toy figures using .020" brass rod where the figure was played with extensively and they have held up.  Straight glue repairs, however, have failed for me even on static 10mm ish connections.

If the joint is small, use a smaller drill and smaller pin.  I prefer thin brass so that if there's misalignment in the holes the pin has a bit of give.  You can also oversize the holes just a tiny bit and fill with a lower viscosity epoxy or superglue.

[jemC]

I am still sourcing for a brass pin. I can't find any online or in my area.

Will those paper clips work?

Edited November 1, 2020 by jemC

[Slave IV]

6 hours ago, jemC said:

I am still sourcing for a brass pin. I can't find any online or in my area.

Will those paper clips work?

I’ve used needles. I cut them with heavy duty wire cutters. 

[Sanity is Optional]

9 hours ago, jemC said:

I am still sourcing for a brass pin. I can't find any online or in my area.

Will those paper clips work?

Try Amazon, look for "brass rod" or "brass wire".

[nightmareB4macross]

On 11/1/2020 at 9:04 AM, Slave IV said:

I’ve used needles. I cut them with heavy duty wire cutters. 

You can also use piano wire. It’s super thin and extremely strong. Just note that you will have roughen the surface to make sure it adds bonded strength to your repair.

[PvtPrivate]

Decided to necro this instead of starting a new thread.

For those who have similar broken arms and are trying to take apart the arm, you might have noticed even after removing the 2 screws you still can't pull apart the arm. This is because of a hidden knurled pin acting as a 3rd screw. Just gently slowly pull apart the arms until it pops off, note its very stuck together because the end of the pin is knurled. After its off, i sanded the knurled bit on mine a little bit to make assemble/disassembly easier.

[arcoregon]

3 hours ago, PvtPrivate said:

Decided to necro this instead of starting a new thread.

For those who have similar broken arms and are trying to take apart the arm, you might have noticed even after removing the 2 screws you still can't pull apart the arm. This is because of a hidden knurled pin acting as a 3rd screw. Just gently slowly pull apart the arms until it pops off, note its very stuck together because the end of the pin is knurled. After its off, i sanded the knurled bit on mine a little bit to make assemble/disassembly easier.

Oh wow! Thank you for sharing. That explains a lot when I tried to repair my arm.  Had to rebuild the shoulder hinge last year too so the pauldron could reattach. 

[PvtPrivate]

2 hours ago, arcoregon said:

Oh wow! Thank you for sharing. That explains a lot when I tried to repair my arm.  Had to rebuild the shoulder hinge last year too so the pauldron could reattach. 

Oh, how did you detach the shoulder? Mine had a crack on the arm attachment

[arcoregon]

On 4/12/2024 at 10:22 PM, PvtPrivate said:

Oh, how did you detach the shoulder? Mine had a crack on the arm attachment

You would ask the hard questions... Haha... There's a screw on the inside that releases the maroon section below the shoulder. After that is removed there is a screw that holds in the swing peg of the arm assembly (at the pivot). The arm assembly lifts up after it's removed. 

[Roy's Blues]

I've been having a lot of success with DAP rapid fuse. It bonds better than any of the regular super glues I've tried.

https://www.amazon.com/gp/product/B01F74M13W/ref=ox_sc_act_title_1?smid=A2OBJKUJFJ62IP&psc=1

[PvtPrivate]

On 4/13/2024 at 1:16 PM, arcoregon said:

Oh wow! Thank you for sharing. That explains a lot when I tried to repair my arm.  Had to rebuild the shoulder hinge last year too so the pauldron could reattach. 

My shoulder hinge finally cracked :') I am sorry to ask again, but how did you take apart the shoulder? Its hard to repair it with the shoulder still attached.

[arcoregon]

The key to removing the shoulder pauldron is the removal of the pin at the far tip. Once you get the separation of the yellow cap from the pauldron, it's a matter of removing screws under the speakers and carefully splitting the pauldron apart. Removing the pin took some careful hammering with a millimeter screwdriver or push tool. Hope this helps. 

[Uxi]

Is this an ongoing problem or something fixed?  Concerned about the Arcadia IFire Valk just got a couple months ago. 

[PvtPrivate]

12 hours ago, Uxi said:

Is this an ongoing problem or something fixed?  Concerned about the Arcadia IFire Valk just got a couple months ago. 

So far its only a problem for the original Yamato VF-19 Kai, Later releases (VF-19S/F/P) fixed the elbow shatter issue, but may still have the shoulder shatter issue as its a design problem. Be careful when handling the shoulders, especially when popping them off from the legs. That's how i snapped mine. When trying to rotate the arm at the shoulder, move the pauldrons down, pinch both edges securely, then rotate. Do not rotate the shoulder pauldron when it is angled up. Or just don't touch them, ever, and leverage the arm to rotate it.

[PvtPrivate]

On 8/2/2024 at 2:41 PM, arcoregon said:

The key to removing the shoulder pauldron is the removal of the pin at the far tip. Once you get the separation of the yellow cap from the pauldron, it's a matter of removing screws under the speakers and carefully splitting the pauldron apart. Removing the pin took some careful hammering with a millimeter screwdriver or push tool. Hope this helps. 

Darn, that is a lot of work and glue to fight through. Another issue of mine is the one that broke is the VF-19S's shoulder, which does not have the pin to open the speaker >.<

I did manage to repair it eventually though, using CA glue, sloppily, but hey it holds together and is mostly hidden anyway. Thank you for replying and for the images!

[arcoregon]

Awesome job! Never looked at my E-Force jets but will probably come across it one day soon. Seems all my plastic is discoloring and getting brittle.