Advice Needed: YAT On Randy Cooper's Star Destroyer V. 2.0

Got my kit from Randy late last week and have been assessing the pieces the last few days.

Like a couple others who have gotten this and posted here, I'm a resin virgin about to lose it with this kit- And I mean that in more ways than one.

I haven't done a full count of all the pieces, but it looks like all the major ones are there. Unfortunately, after about 60 castings, it looks like a good number of these molds are already shot because some of the warping I have seems pretty significant. And it's warping that isn't present on other people's kits.

Going in, I knew I was signing up for a project that was going to require a learning curve and a good bit more improvisation than something like the Zvesda/Revell kit (which I still haven't finished).

Working on that one though has given me a familiarity with the basic structure and how things in general should look and what goes where.
I thought that would give me a good footing to start, along with Randy's attempts to simplify the build with how he cast the pieces this time.

Unfortunately this is the kind of stuff I'm running into



As you can see, the left hull piece is elongated about 1/2 to 3/8". It's not just warped, it's distorted.

I knew when I ordered it I couldn't expect Randy to hold my hand and walk me through every problem, but I reached out to him anyway with some thoughts on how to address this and only got back the general rote answer - run boiling water over it and press it into shape and then run cold water to set it.

The way I see it, there are only two options to fix this piece.

The first would involve building a jig using the mirrored right side piece, which I'll have to take for granted is "true".

I would take an outline of it (bottom up to trace) and then have 1" x 2"'s around three sides in a shape like this



After the hot bath, while the piece was pliable, I was thinking I would be able to slide it into the jig, and then use Rob Rossi's system of weighting it down with a bag of sand while it cools.

Thinking about it some more, is it foolish to expect the resin to essentially contract vertically while remaining the same horizontally?. More than likely, I would guess forcing it into a narrower constraint is simply going to cause the middle of it to start buckling...maybe even rippling in waves? There is a good 1/4"+ that needs to be reined in.
That seems like a lot to me.

The only other option that I can see is to make a cut and trim out a 1/4" sliver either in this area here, or below closer to the exhaust end.



The problem there is, the elongation is distributed evenly across the interior cut out. Taking a chunk out of one area is going to throw the interior dimension off.

So- which of these two options seems the most viable?

There are a bunch of other pieces that have, what i assume are, the more typical banana effect going on. They need to be made pliable and then tamped down flat, or constrained. This is the kind of stuff I was fully expecting (just not on nearly ever main piece).


One that I'll post a pic of later, is starting to twist like a pretzel and some of the long trench pieces have warping on both the x and y axis.

But it's that hull piece that I think is going to vex me the most.

Welcome to the wonderful world of garage cast resin!
I would extend the right hull with some styrene, since the
inner space is not going to be visible.
But then again, I haven’t seen the new kit in person.

Hey Nils, Thanks for the response.

I'd thought about extending the other side, but the problem is the side wall trenches, and the bottom hull both have to line up properly. There's only one piece stretched out of kilter.

Then again, it might be easier to add styrene to the side trenches and bottom hull, along with the top, rather than trying to take something away from that elongated piece.

Is it foolish to think that I'll be able to basically contract that hull piece with a long enough hot water bath? I thought having a jig to constrain it into would be what I'd need, but I'm thinking now that's just likely to make it buckle and bow up in the middle. I'd use a sandbag to try to keep that from happening, but if it's heated up enough for the core to be pliable, I guess that would be enough to ruin the surface form and detail as well?

Maybe I shoud add 1/8" to the right side, and cut out 1/8" from the left.

I was fine with the notion that I would have to add some thin strips of styrene here and there to fill in seams on sub sections and details, but I never expected on a brand new kit that's only had 60 castings, to have make major corrective repair to the fundamental structure.

Can't Randy send you a replacement piece?

I would trace the non warped hull side on thick styrene,.cut that out and flip it over to have a perfect mating side.
I would then cut up the warped hull piece and glue that on the styrene,...as long as the end side matches up to the engine section and the guns match the other side and the front side matches aswell ,.i think you will never notice you restored(cut up) that side after puttying and painting.

Are the guns(wells) expanded aswell?
If that's the case, forget about not noticeing the restoration.

Anyhow i would ask Randy for a replacement since cutting up means almost scratch building that side,.this is not what i would expect from a quality resin kit from a reputable producer.
I think this kind of surgery also goes beyond statements as "for experience builders only"and"scratchbuilding techniques required"
You might aswell just includes one hullside in the kit and say "for the other side just copy in reverse the included part"(ok this statement is maybe a bit extreme but it borders on the same territory)
I even suspect that eventhough the version 1 SD was difficult to build,.it was buildable with enough patience and experience,..without enlarging or shrinking complete hullpieces.
I thought that this version was more builder friendly:confused
I was on the fence of getting this kit,.for now i changed my mind
Although i think Randy Cooper is someone who is a reasonable person and might send out a replacement part(for me personaly he has been very easy to deal with in the past),i thought that he had better quality control before sending kits out.
Chances are that only this part slipped through the quality controll though.
Does anybody else have the same problems with this kit?

This may not be of any help, but those problems don't look like the result of shot molds to me....a mold that's failing will start to disintegrate, leaving little chunks of itself in the castings. The subsequent castings will have little blobs of resin in place of the lost piece of the mold. A mold can be distorted permanently if stored improperly, but that's not necessarily a sign of breakdown. Also, a mold can be distorted temporarily while the parts are being cast if care isn't taken to keep it true...it's flexible rubber, after all. This may not even be Randy's fault: if it was very hot in the delivery truck (or plane) parts of the kit may have warped due to heat exposure.

Looking at the pics you posted, starting with Randy's suggestion may solve some of the problems simply...you might be surprised by how much shaping you can do to do warmed-up resin parts. I've been able to significantly reshape things just by letting them sit in the sunlight. If the parts don't seem to be bending, they're not warm enough...and if they're warmed up too much, they'll sag right in your hands.

Hope this helps and good luck!

I had to boil most of mine in water to straighten my pieces out . almost all of them were warped in one way or another. It took a lot of time and stress. And even after there were some warps that I just couldn’t get out. And there were a ***** ton of bubbles. It was by far the hardest build I’ve ever done. Good luck and take your time and check and double check and triple check everything.

Voodoocaster said:

.
...
Are the guns(wells) expanded aswell?
If that's the case, forget about not noticeing the restoration.

Anyhow i would ask Randy for a replacement since cutting up means almost scratch building that side,.this is not what i would expect from a quality resin kit from a reputable producer.
I think this kind of surgery also goes beyond statements as "for experience builders only"and"scratchbuilding techniques required"
You might aswell just includes one hullside in the kit and say "for the other side just copy in reverse the included part"(ok this statement is maybe a bit extreme but it borders on the same territory)
I even suspect that eventhough the version 1 SD was difficult to build,.it was buildable with enough patience and experience,..without enlarging or shrinking complete hullpieces.
I thought that this version was more builder friendly:confused

Click to expand...

Yeah. I was especially enthused about this kit because of all the time and frustration saving mods he'd built in. There's a great interior support structure already designed in that you can easily bolster on your own, along with some super structure, engine, and tower changes that looked to make things much simpler this time around.

But now I've got to devote a lot of time and energy (and a little more cash) to even just get to the point where I simply start general test fitting,

As far as getting a replacement cast- when I reached out to him I sent him pics of how far the piece was off along with a diagram for the proposed jig to correct it. He didn't acknowledge those at all and just gave me the boilerplate (npi) response to run boiling water over it.

Going through his directions/photos though, I reached this one at the end which is the only one that is identified as "troubleshooting"



I hope he doesn't mind me posting that here. If I did just line everything up right now using the lower left hull piece as the starting point, I would have a gap on the right side there.
However there would also be a large gap where the four hull pieces join and another gap between the top and bottom left hull piece where they connect along the trench side because of the way that lower hull is slightly angled out as you get to the center join.

Before requesting any replacement, I would really like to try fixing it on my own. I don't expect it to be fun, but it would be a good learning experience.

Most of these pieces including the tower, all the trench sections on the main and super-structures are warped. One is even warped both length-wise as well as top and bottom like a pretzel twist. I figure getting those pieces taken care of first will give me a better understanding of how the heating and setting process will go when I finally am ready to tackle the big section.

Oddly enough, the only pieces that don't seem warped whatsoever are the interior support pieces. Those all appear true, or close enough that once assembled, they should be already pulled in the proper directions..

I was on the fence of getting this kit,.for now i changed my mind

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Right before I sent him my payment, he told me he had finished shipping out the first forty kits, and had another twenty order to fill. So my kit was somewhere around the sixtieth casting he made. I don't know how much that figures in or at what point he will make new molds.

As Don says, it's entirely possible it could have just warped during shipment. I know at least a few other people closer to the first batch of twenty or so don't have hull pieces with this problem. I would be very curious to know if anyone whose received theirs in June also has the same anomaly as mine, or if I'm just special.

E3kehoe- is that the Cooper V2 Star Destroyer you built? If so, that was a damn quick job!

I just bought a respirator mask and am waiting for a sunny morning to go outside and start removing the flash and doing a prelim sanding of all the pieces.
I've heard Randy doesn't use mold release, but I'm going through and washing everything first too, just in case

In fact, I'm going to go down and wash another batch in a few minutes.

Thanks for all the replies and info so far, guys. I very much appreciate it!

The warping could be from transportation; it could be from taking the pieces out while the casted resin is still soft. My theory on why it's warped is the material used for the mold. Randy seems to use a very soft silicone, which is better for picking up fine details and easier casting removal. In other words its flexible enough to pop parts out like a silicone ice cube tray. The problem is that his parts and molds can be very large, and if he is not careful, the mold can be laid down in a slightly "off" manner before pouring the resin. If the mold is off, then the casted part will be off. Imagine if I had a mold and I bent it like a banana, and then I poured the resin. The part will come out bent like a banana...
Essentially, the part is still true to the mold. It just needed more care in its handling. At least that is what I think happen.

I've found that firmer silicones, shore hardness over 30, still pick up all the detail and are less likely to be distorted...It also helps if you make the mold a bit thick so it will be more likely to hold its shape. More expensive to use more RTV but it yields better parts. One area where stiff RTV isn't ideal is where undercuts are pronounced.

More pics to come soon.

I washed a few more of the parts last night- trenches, superstructure, etc. and then took the time to more closely look at the hull differential. It's off by 3/8" not 1/4- closer to one half inch.
That extension is spread through three quarters of the length going forward. It starts in the bank of gun turrets, so those get incrementally off the more forward you go.
Also the piece as a whole is already bowing up in the middle slightly, when you look at strict profile. Tamping that down would only spread the piece further out (minutely, but still it wouldn't help to contract it, which is what is needed.)
It's also of differing thickness across the piece- probably >1/8 from the thickest part to the thinnest.

Also, I'm seeing lots of pink goobers on many of the pieces. I thought maybe Randy had a small cut and a few drips of blood got into the resin when he poured it, but now I'm thinking this might be bits of the mold coming off?

will post pics soon to illustrate.

Looking it over again last night, I'm losing the confidence that came with ignorance I had. I doubt there is anything I can do to this piece to rectify the distortion that was baked in, short of scratchbuilding a replacement for half of it.

DonS said:

This may not be of any help, but those problems don't look like the result of shot molds to me....a mold that's failing will start to disintegrate, leaving little chunks of itself in the castings. The subsequent castings will have little blobs of resin in place of the lost piece of the mold

Click to expand...

would that be like this



I'm guessing the rubbery pink boogers are pieces of the mold. They're set in the resin (present on six or seven various parts at least) so getting them out and the piece cleaned up is another thing on the "to do" list before I move on to test fitting.

Those are pieces of the mold. You can see that sometimes (on a much smaller scale) on the first pull...irritating when a little piece of the mold comes off on the very first part you make, but it happens. Usually, when a bit comes off on an early pull, that was a piece of the mold just waiting to go...and once those early bits (if any) are gone, the mold should be stable until it begins to fail.

But it might be just a piece or 2...you shouldn't see bits coming off to that extent on a newer mold. I wonder if Randy uses mold release? I've heard people say it just isn't necessary, that since RTV doesn't stick to much of anything except itself, that mold release is superfluous...but I don't think anyone would argue it doesn't extend the life of a mold.