Review of Wurth's Replast, a plastic repair product

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JonW
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Review of Wurth's Replast, a plastic repair product

#1 Post by JonW » Wed Apr 27, 2016 11:32 pm

We dont usually review products I know, we usually just moan about them when they dont work (well I know I do LOL!). So, since I've found something that actually works I thought I'd do what I consider more of a 'real review' for the forum, hope you find it useful. :smt001

As regular readers of my build threads may know I do enjoy (term used loosely if i’m honest) a bit of plastic repair. I’ve played with quite a few of the options over the years, I think I was forced to as I crashed quite a lot LOL! I started with fibreglass patches in the 80’s just like everyone else did, and we all know now that GRP and plastic don’t mix at all, but back then it was all we could get. Obviously there are two types of repair, those like good old GRP that sit over the crack/gap to bridge it, and those that melt the original plastic to repair it, forming the separated parts back into a single piece. The latter being the more preferable of the two. After trying a lot of the well known commercial products that people rate (eg. plastex – I found that it was smelly and made a brittle repair), and some I’ve read about or friends suggested (eg. acetone and plastic chips - didn’t work for me at all as it didn’t even mix; plumbers glue – that I found it made a brittle repair) I went back to what worked for me, plastic welding.

So, for the past few years I've stuck with my trusty soldering iron. While I’ve read that some people have struggled with this method and compalin of brittle repairs (too much heat and over use of said heat in one spot perhaps?) I’ve had no such problems and can only think that my 'technique' (term again used loosely) and the type/wattage of the soldering ‘gun’ that I use has saved me their pain. I did a write up about doing such repairs and stand by the fact that while you have to avoid breathing in the fumes, for me this method makes flexible, un-brittle repairs even in our old semi-brittle panels and those whove been to my shed have seen these repairs and can attest that they do what is needed : http://2smoked.com/Repairing_Plastic_bodywork.html" onclick="window.open(this.href);return false;

Anyway, last year a friend of mine suggested I try Wurth Replast, he’s a rep for Wurth and felt I would be impressed with it. We all know Wurth make good products, so he had peaked my interest. Wurth’s Replast is a 2 part adhesive that uses a clever nozzle that uses twists and turns inside to mix the two parts to have a workable product come out the end, so no mixing on a bit of old cardboard like you have to do with other two-parters like Araldite, JB Weld etc. FYI the product sets in the nozzle so you just leave it in place to seal the package and fit a new one when you need it next.

Image

The ‘glue’ itself is very sticky and you don’t want to get any on yourself or your clothes, it will stick like the proverbial to a blanket that’s for sure. The biggest surprise for me was that it works very well as a filler (more on that later) and repairs didn’t reopen when twisted so I believe it is bonding well between the surfaces. As far as I can tell, Replast does not melt the plastic surface it just sticks to it very well. It enjoys its own strength so backing the repair with more product creates a stronger repair, that remains flexible. What you can also do is use a fine mesh tape embedded in the replast for added strength as well, and polythene sheet works well to leave a smoother top surface, saving time on rework after its set. Thickness of product doesn’t seem to be an issue, it sets up solidly throughout any blob and can be filed, sanded and drilled just like, well, plastic. To all intents and purposes you can think of this as a 'plastic in a tube' as I expect you could make parts with it as well, though I didn’t try that.

Working time for me was very quick and I could feel the product becoming thicker in the nozzle after only just squirting some out, moving it into place and then going back to use it again for another repair. This means that you would need quite a few nozzles for doing bike panels, unless you form some kind of production line and maybe had a helper to work the material into the repair while you moved to the next repair job. The upside of this fast setting is that you can get on with sanding, drilling and other work very quickly, certainly within the same hour. Of course, that is expected really, this is an industrial product as used by the car bodywork trade, where I believe they find it especially good for bumper repairs. Naturally they need a fast set so they can get on with the job. Time costs money for them, less so with us DIY'ers of course.

So, am I impressed? Well, Yes I am. It's the best of the potions and products that I've tried, hence I felt it was worth reviewing. It has very little smell (I didnt worry about it being toxic thats for sure), sticks to plastic (and my fingers) very well and sets up very fast indeed and is ‘solidly flexible’, allowing it to be sandable enough to be finished just like the normal plastic parts of the panel.

It's the repair/filling aspect that I think that I like most about this product as being a glue made for repairs, any filling you do also strengthens the join/panel as it sets up ‘locked to the panel’ plus it has its own structure and strength, most unlike an actual filler which adds no strength of course.

Some (admittedly not wonderful) pics of some of the repairs I did with this product:

Blob filling, once sanded this will be clean fill of a small hole.

Image


Filling and strengthening fairing ends. I used poly sheet when the glue was wet, smoothed over the sheet with a spatula to leave a flat repair and removed that sheet once set, the sheet can be reused an comes off cleanly, just needs sanding now.

Image


Sanded repair (was sheeted until set, then sanded). You can see how the glue has acted as a filler in the ground out portions and this filled a nasty wide V gouge from a previous (still solid Pro welded joint) repair and held old weak body filler until I ground it out. Much stronger with this repair and wont split, crack and fall out with heat or vibration now.

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Re: Review of Wurth's Replast, a plastic repair product

#2 Post by evan_calgary » Thu Apr 28, 2016 2:46 am

Looks quite similar to the JBweld plastic 'weld' product that I use, after sanding. It works excellent. The soldering iron produces a very brittle part that cannot handle vibration or stress. Seen far too many broken 'melted' plastic repair parts. This includes professional plastic repair. The JB will take minor stress and can also be used as a filler. If this is similar product you should have good results.

Does anyone know what was used in the 80's/90's as a plastic bonder? I see thick gobs of this stuff used to repair. Its stick only moderately well and really stinks when sanded.

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Re: Review of Wurth's Replast, a plastic repair product

#3 Post by JonW » Thu Apr 28, 2016 3:20 am

Evan, honestly I kid you not, Ive welded plenty of panels and the repairs are as flexible as a flexible thing. If you do it right its not brittle at all, but I wont convince you I know. Your issue with this method of repair is one of the reasons I said what I did above and why I keep trying new things, and that I reported it here. What works for me seems not to work for you. If the panels are the same, the technique/tools must be what's different. As I mentioned I wrote up a 'how to' and I dont see what more I can do to explain the process I use, so I can only think the old panel plastic may well be some of the issue youve seen. For some reason we dont get too many brittle panels in Aus, maybe the cold other countries see is the issue, perhaps the generally warm climate here is kinder to plastic? Anyway, to suggest that all plastic repairs using a heat/welding are brittle is wrong as its just not true.

FWIW I think the 'plastic bonder' youve seen might well be GRP resin, Ive found that smells terrible when sanded, but then so does some filler of course. GRP resin sticks well enough to panels but has no strength and doesn't really hold any repairs properly and is very brittle of course.

Anyway, back to glues... I've never seen JB Weld plastic repair stuff in the shops here in Aus, must be coming tho as we do usually get stuff, it just takes time. Please do feel free to do a review of it (with pics of course!) as I (and others too im sure) would be keen to see it in use.

And... For those interested in this product, I will put up some more photos of working with Replast when I get round to it...
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Re: Review of Wurth's Replast, a plastic repair product

#4 Post by South_Oz » Thu Apr 28, 2016 4:33 am

Nice write up as usual Jon. Ill get some when im out shopping next although I cant think of anything at the moment that I can use it on.

Dave
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Re: Review of Wurth's Replast, a plastic repair product

#5 Post by JonW » Thu Apr 28, 2016 6:07 am

haha, too funny. I do reckon you could make parts with this stuff, so knowing you Dave that will be more your thing :)
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Re: Review of Wurth's Replast, a plastic repair product

#6 Post by yamasukiman » Thu Apr 28, 2016 6:13 am

Hullo Jon,

what sort of price is this product?
Like you I've tried a few different methods of repairing plastic panels without total success so I'd
be keen to try it.

Cheers Ian.

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Re: Review of Wurth's Replast, a plastic repair product

#7 Post by RuZty » Thu Apr 28, 2016 9:11 am

I looked this up on their US site and it is about $55 for the 7oz tube Jon shows. You would also need the 2 part dispenser gun. They also show a 10oz tube that is sold as 2 standard squeeze tubes, which was about $48. This is more economical, and you don't lose the volume of the mixing tube each time, but also not as convenient as the dispenser tube. It is described as a 2 part epoxy and sounds like it sticks to everything, including steel.

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Re: Review of Wurth's Replast, a plastic repair product

#8 Post by JonW » Thu Apr 28, 2016 9:46 am

Ian, best to talk to your local Wurth rep as not all products are available in Aus.

FWIW I do like the clever mixing tip, but yes you do need the 'gun' to use these twin cylinder units and yes you do sacrifice the volume of product in the tip each time, which is small, but yes it is still wastage.

I did have a mishap (dont ask) with another tube of this product and mixed some of it by hand, and its fine if you get the two parts equal in the mix, but some of it had too much of the black (rubbery) part and not enough of the grey (solid setting part) and it was just a rubbery mess you could peel off with your thumb, so I would advocate the mixing tip version if you dont think you can meter out the right amount each time.

Yes RuZ, it is very sticky when fluid and sets up with a flexible joint, so as long as it adheres to the two surfaces then I cant see any reason why it could not be treated as a bond. You would need to assess the strength of said bond for your application, but it does feel like it would work on things other than plastic, tho that was not part of my testing of course, same as I didnt check it for resisting petrol etc, there was no need in a bodywork application as its plastic panels covered by paint only for my needs.
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Re: Review of Wurth's Replast, a plastic repair product

#9 Post by RuZty » Thu Apr 28, 2016 10:14 am

Good review Jon, I agree the dispenser gun is way easier for 2 part adhesives. I always try to make 2 lines that look identical when using regular tubes, but if one part is thinner than the other it can be challenging.

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Re: Review of Wurth's Replast, a plastic repair product

#10 Post by kpke » Thu Apr 28, 2016 11:30 am

Nice one as usual Jon W. Thank you for posting this!

There is a video from the manufacturer here.


https://www.youtube.com/watch?v=a_Ig_qtB-1g

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Re: Review of Wurth's Replast, a plastic repair product

#11 Post by hablair » Thu Apr 28, 2016 12:20 pm

at a push you can use an araldite plunger set, it will work and will be cheaper than the gun, there are two guns available here in Aus a plastic type and a more durable metal one, believe it or not the metal one is cheaper

10 oz we don't have here, its the same with any two part glues, you need the correct quantities

As for making parts I'm not too sure if it is rigid enough for that, that said if a conical type tab breaks off just squirt some into a cone shape, spray the screw with say Rost Off and push it into the unset cone, when cured wind it out offer up the panel and put your screw back in

And yes I 'am the Wurth rep who sent Jon the tube, I'll plead guilty to any arguments caused LOL

Jon thanks for your review

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Re: Review of Wurth's Replast, a plastic repair product

#12 Post by MK » Thu Apr 28, 2016 1:40 pm

Nice advertising :-)
Unfortunately in Germany they only sell to registered companies, but there are some resellers on amazon or ebay.
Lowest price I found was 18.90 Euro for 50 ml.
Bye
Martin

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Re: Review of Wurth's Replast, a plastic repair product

#13 Post by evan_calgary » Thu Apr 28, 2016 1:45 pm

Fair enough. I will do a review when I get a chance. I suspect I have gone through 20 tubes of the stuff this spring. I get your point on the melted plastic repair, just my experience to date. I would be interested in testing a part that has been properly repaired.

JonW wrote:Evan, honestly I kid you not, Ive welded plenty of panels and the repairs are as flexible as a flexible thing. If you do it right its not brittle at all, but I wont convince you I know. Your issue with this method of repair is one of the reasons I said what I did above and why I keep trying new things, and that I reported it here. What works for me seems not to work for you. If the panels are the same, the technique/tools must be what's different. As I mentioned I wrote up a 'how to' and I dont see what more I can do to explain the process I use, so I can only think the old panel plastic may well be some of the issue youve seen. For some reason we dont get too many brittle panels in Aus, maybe the cold other countries see is the issue, perhaps the generally warm climate here is kinder to plastic? Anyway, to suggest that all plastic repairs using a heat/welding are brittle is wrong as its just not true.

FWIW I think the 'plastic bonder' youve seen might well be GRP resin, Ive found that smells terrible when sanded, but then so does some filler of course. GRP resin sticks well enough to panels but has no strength and doesn't really hold any repairs properly and is very brittle of course.

Anyway, back to glues... I've never seen JB Weld plastic repair stuff in the shops here in Aus, must be coming tho as we do usually get stuff, it just takes time. Please do feel free to do a review of it (with pics of course!) as I (and others too im sure) would be keen to see it in use.

And... For those interested in this product, I will put up some more photos of working with Replast when I get round to it...

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Re: Review of Wurth's Replast, a plastic repair product

#14 Post by MK » Thu Apr 28, 2016 2:25 pm

BTW: Over here they offer two versions:
The "fast" one that you describe and a "superfast" that cures within 25 s and can be grinded after 5 min !
Maybe the latter one is a bit too much for us home DIY'ers ?
Bye
Martin

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Re: Review of Wurth's Replast, a plastic repair product

#15 Post by JonW » Thu Apr 28, 2016 7:04 pm

Martin, I reckon the one I have is the Superfast version, it sets up very quickly indeed. In the video the guy ambles about cutting stuff and going back to the job, the version I had certainly would be starting to set up by then. I agree the slower set is the one to choose for DIYers. Interestingly you can buy Wurth direct from the local reps here, but if not many car/bike businesses would be able to get it as most have their own rep.

Evan, Id love it if we all lived down the road from eachother and could drop round for a bike evening once a month, we could all have had a go with this stuff and maybe destruction tested some products as well LOL Please do review the JBWeld (and anyone else who wants to do one, Im always interested to hear about new things).

Howard, Yes thanks for hooking me up with the product. I bought my 'gun' on ebay, its crappy and had to be modified, where did you see the metal gun? I think youre right about making any kind of load bearing part, I was more thinking about a cover, but it would certainly repair a missing tab etc.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

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