Have a 1/9 R75 + Sidecar model, that has rubbery/vinyl parts for things like seats.



My previous experience with this stuff on a 1/9 R75 was lass than stellar. No glue I had seemed to be able to stick to it even after I scrubbed it of any possible mould release agents.

Tried super glue, and epoxy, and even Plastruct plastiweld which I have had great success on a variety of other plastics. When dry the glue would simply flake off.

Paint was even worse at adhering, and would come of with even with gentle handle. even the slightest flexing resulted in almost total unpainting.

At worst I can always use some silicone to make resin replacements, but would prefer to use the kit part, so any suggestion on how to handle this material would be greatly appreciated.

Hi Iain,

the only thing I can think of is a contact adhesive. I have recently been using ' Ados GreenStik' on those dreaded plastic/rubber tracks with pleasing results. It's water based, environmentally friendly etc. I assume it or something like it would be available your side of the ditch.

cheers
David

Given that even paint won't stick, I'd go the resin route if I was you. My only caution would be to coat the parts in vaseline or similar mould release before pouring the RTV silicone, just in case it tries to bond with the parts!

Use of these vinyl "rubber" parts in plastic model kits should be a criminal offence! Too many manufacturers think they are being clever, giving our "toys" these cheesy parts... (Kinda like gun barrels with "recoil action" springs.)

Tom

Might give the contact adhesive a go. Probably the one glue I haven't tried.

Also have some etch primer lying around. Contains phosphoric(?) acid to help it adhere to metal. No idea if it will have any affect on this stuff but what the hell.

If those fail I suspect resin will be the only thing left.

Cyanoacrylate (Super Glue) will hold the vinyl just fine to plastic parts.




Not necessarily true. To get paint to stick to vinyl, simply paint on a coat of PVA glue (Elmer's School Glue or a similar brand) first. Once dry, the paint will stick to it with no issues.

Superglue definitely won't hold this stuff. Tried it on an inconspicuous spot in the hope it might be different to the last stuff I had, and after a good 12-16 hours to cure it just rubbed right off with the lightest of pressure.

I looked at some photo's briefly on this kit. It looks like all of the rubber parts have posts on them. The plastic parts have matching holes.

Maybe the vinyl parts are supposed to be a press fit with no glue, like a snap kit?

I don't have the kit in front of me, so I could be very wrong. Just looking at other build logs of this, nobody mentions gluing or the difficulty thereof for the vinyl parts.

Maybe a private message to this guy might give you more insight. It looks like he was able to paint his seats......

https://aeroscale.kitmaker.net/forums/170006

That is an awesome job on the model. I am afraid to even touch mine after seeing that one.

I totally agree!!

Anyway, if I were you, I'd make some resin copies or some scratch jobs in plasticard. It would be the hardest and the longest way, but also the most effective one. It seems to me quite strange that you can't glue them with super glue.

Have a good luck

cheers

Resurrecting this post as I am currently in the process of repairing my 1/9 R75 which had been damaged over the course of 4 house moves in 4 years. In addition I have 4 other 1/9 scale kits that have this horrible stuff, whatever it is actually made of.

While I am in the process of preparing to create a silicone mould to cast replacements, I figured I would add more info about other things I have tried to get glue and paint to stick.

Tried the etch primer that contains phosphoric acid for no appreciable result, paint still rubs off easily. Not really surprised by the result.
Scuffed up a piece with sandpaper and it helped a bit, but only due to the paint sitting in the sanding scratches. On the surface it still rubbed off with little effort.

Painted one of the pieces that fell off with some Humbrol enamel, and while it seems to be working I have my doubts. My experience with enamel on rubber is that it never really dries and remains tacky. Will know for sure in the next 24 hours.

Additionally as a bit of an experiment, I cut some sprue pieces off and dropped them in different solvents I had handy. 1 piece went into some white spirit, and another in some 100% MEK. Will examine them in the morning, though I fully expect them to be unaffected.
That pretty much leaves me with kerosene or petrol to try as a glue, and they seem a little impractical if they actually worked.

Try Shoe Goo.

In the US, BSI (Bob Smith Industries) makes two types of flexible cyanoacrylates especially for rubber products that will definitely glue rubber materials-- I know as I've used both to glue a chunk of tire back in that I "accidentally" gouged out on an all terrain tire on my Hyundai Santa Fe a few years ago-- it's still holding four years later. The other is a "foam safe" super glue used to glue styrofoam products together. These glues are primarily used for flexible rubber control surfaces in flying model aircraft and rockets. I've also used this stuf to repair vinyl seats in 1:1 autos, and glue the vinyl parts of some Dragon spacecraft kits together. The BSI glues can be painted too.
VR Russ

Found a couple of tubes of contact cement and am experimenting on some pieces that I plan on replacing with brass sheet. Should know later today how effective it is and if it is worth continuing with.

Also, it turns out Humbrol enamel does seem to adhere much better than any of my acrylics. Can still be rubbed off but required significant effort, so should survive normal handling quite well. My limited range of colours in enamel mean I will have to use the enamel as a primer coat for some pieces and finish in acrylics. If the contact cement works out ok then casting in resin should not be required.

My experiments with MEK and white spirit did absolutely nothing to the scrap pieces immersed in them.

On the Italeri 1/9 WLA I built, I was able to get the vinyl seat and air hose attached with Gorilla Glue, but I don't know about availability outside the US. There are some products used to patch vinyl-I just picked up a tube as well to try on other items. After four years there must be an improved formula that will work.

Hi,
I remember to have built this kit with the Esci brand when I was a child, and I don't remember difficulties in fitting polyethylene pieces. Probably they simply fit without glue.
If glue is necessary, you could make some crossed deep cuts in the gluing area and use cyanoacrilate; this won't adhere on this soft plastic, but it will create a mechanical anchorage to keep it in position.
I don't know any solvant attaching PET. Many bottles of solvants are made by PET themselves.

Some pieces certainly are easy to attach mechanically. The fuel tank pads for example have long stubs that fit in holes, and once placed careful application of heat will secure the stub to the inside of the tank.

The larger pieces however, like the side car seats, or the rear seats on the Kettenkrad, are simple butt joins along the narrow bottom edges of the pieces, which means there is not a lot of gluing area, or area in which to make cuts to obtain a solid mechanical joint with glue.

Unfortunately my initial attempts at a silicone mould have not fared well. The smaller pieces are ok but the larger pieces have bowed inwards under the weight of silicone, so I will have to try and reshape them a bit with hot water and make another attempt. Next time I will ensure I provide adequate internal support to prevent another collapse.

Wasted silicone or learning experience?

Just one other point regarding vinyl, which may or may not be relevant depending on the exact chemical nature of different manufacturer's vinyl. I recently brought an Italeri Opel Blitz out of retirement, having assembled it around 15 years ago, and the vinyl tyres were well into the process of turning to a semi-liquid goo. And so were the plastic hubs where they were in contact. I know there's an acid involved in vinyl. All that time the truck had been stored in a display cabinet on a glass shelf in conditions comparable to a good wine cellar; in darkness 99% of the time, constant temperature around 15C. They hadn't needed gluing, they just stretched over the hubs and the only chemical contact was the acrylic paint coat on the hubs themselves.

So all I'm saying is there's a question mark over the longevity of vinyl itself before you even start mixing it with solvents or other glues. I don't know when the Blitz tyres started degrading but at a guess it must have begun after 7 or 8 years.

Cheers, Tim

That's a process familiar to many. I had that happen to several Airfix armor kits where the vinyl melts all over the plastic. More recently this has been an issue with DS track.

So depending on the amount of certain chemicals in vinyl it will melt eventually as the acid leaches out if it. But this is not all. Some actually do the exact opposite, cracking and discintigrating.

The best solution is probably the old school one and use regular epoxy cement. Or go to a sporting goods and find pool liner or tent repair cement. It's made for vinyl.

Because I can't leave well enough alone, I decided that since none of the solvents I have on hand affect this stuff, that my only other option is flame testing to try and identify the actual plastic.

Result:
Hard to ignite with standard lighter, starts to liquefy before ignition.
Once ignited, burning can be sustained if flame is initially directed into more material, ie held at a slight downward angle so the fire moves up the material. Otherwise the flame will extinguish fairly easily at the start.
While burning liquid plastic drips off.
Flame colour is blue with orange edges, looks almost identical to the lighters own flame, no visible smoke.
Slight acrid smell.

Based on the info I could find on various sites, it's flame behaviour seems to match the behaviour of nylon rather than vinyl or styrene.