Polyester resin and paraffin wax

Ian_Edwards

Ian_Edwards

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I need a small amount of paraffin wax to add to some pigmented polyester resin to make a small repair to some gelcoat damage.

In the past I've bought it at the same time as I bought the resin, but now I have plenty of resin but no wax additive.

Is the paraffin wax the same as liquid paraffin wax I'd by at a chemist?

Or is there an alternative I can buy on the "high street"?
 
Liquid paraffin is a highly refined mineral white oil!

Might work but I'd not risk it ... but you could do a trial. You'd need very little .. the wax in styrene solution is about 10% wax and you dont use very much of that

For a small repair cover with adhesive tape or film or fill slightly proud and rub down.
 
The wax is usually supplied as 'wax in styrene', i.e. dissolved in stryrene. I'd be inclined to stick to the real thing.
You could probably order on-line and have it before the weekend. I've always found East Coast Fibreglass Supplies helpful and efficient.

Alternatively, covering the curing repair with a suitable tape will exclude air and allow it to cure fully. I presume you're intending to rub down the repair to a finish, anyway?

( I see the sage-like Vic got in there as I was typing. No harm done.)
 
East Coast Fibreglass supplies charge £1.95 for 100g of wax in styrene.

and

£21.50 for delivery to the Highlands, in this case Inverness!

That's why I was looking for a local alternative. The local chandlers don't stock it.

I've tried the cover it with tape or cling film techniques, but never had much success, I alway end up squeezing the filler "out of shape", especially when trying to repair corners.
 
Are there any candle makers near you coz they use parafin wax. There used to be one on the old A9 just outside Inverness on the way to Dingwall - say about 2 miles past Caley Marina entrance. I think they were called Northern Candles or something like that.
Can I ask, what does the addition of candlewax do?
Mike
 
Vegable said:
Can I ask, what does the addition of candlewax do?
Click to expand...

I don't know if it actually is paraffin wax, but the normal "wax in styrene" migrates to the surface of the gelcoat where it forms a skin that excludes air and allows the gelcoat to cure properly. Gelcoat in contact with air remains slightly tacky (which is not necessarily a problem if you're going to sand it down anyway).

Pete
 
Vegable said:
Are there any candle makers near you coz they use parafin wax.
Click to expand...

prv has answered you about what it does.

The availability of paraffin wax is neither here nor there: the wax in "wax in styrene" may or may not be paraffin wax. I've no idea, although I've seen it simply described as "paraffin". But to be effective it's dissolved in styrene (about 1:20), which probably isn't so easy to find.
 
I solved the problem by ordering from easycomposites, 250ml of wax in styrene (a lifetime's supply I'm sure) @ £3.95, delivery "just" £5.90.

Inverness to Glasgow is 340 miles round trip, about 7 hours to drive, roughly equivalent to driving from London the Manchester (without any motorway) for tin of wax in styrene?????????????

But thanks for the replies, they were really useful, I didn't understand what the "wax" you add to polyester was, I didn't know if candle wax or liquid paraffin wax would do the same job. But it's now clear, it's a mixture of about 10% wax dissolved in styrene.

I've also found that gelcoat applied without the wax clogs sandpaper/wet and dry very quickly, until you've sanded off the surface layers.
 
I've used the colour matched gel coat repair kit from ECFS on our club 'plastic' gigs. The kits contain a small quantity of release film to cover the repair with whilst it cures. I've found this to be very effective. No idea if it'd help the OP who seems to have solved his problem anyhow but worth bearing in one for the future?
 
My understanding is that the wax settles on the surface to prevent air from getting to the cured top layer.

Now I am not an expert but I am sure that when you rub the top say 0.05mm(??) surface layer of the epoxy off don't you expose epoxy that has not been 'protected' from air anyway? So with repairs that can be left proud and rubbed down do you need to use wax??
 
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paella said:
My understanding is that the wax settles on the surface to prevent air from getting to the cured surface.

Now I am not an expert but I am sure I that when you rub the top say 0.05mm(??) surface layer of the epoxy off you expose epoxy that has not been 'protected' from air anyway so with repairs that can be left proud and rubbed down do you need to use wax??
Click to expand...

do as VicS said. tape up & rub down
 
paella said:
Now I am not an expert but I am sure that when you rub the top say 0.05mm(??) surface layer of the epoxy off don't you expose epoxy that has not been 'protected' from air anyway?
Click to expand...

No - because of course layers below the surface are protected by those above them.

(And this only applies to gelcoat, not epoxy)

Pete
 
If the OP has a problem with the over-taping or over-filming distorting the filled profile, could you not wait until the bulk of the mix has gone off, leaving just the tacky surface layer and then apply the film and allow the surface layer to finish curing?

Or doesn't it work like that?
 
skyflyer said:
If the OP has a problem with the over-taping or over-filming distorting the filled profile, could you not wait until the bulk of the mix has gone off, leaving just the tacky surface layer and then apply the film and allow the surface layer to finish curing?

Or doesn't it work like that?
Click to expand...

Not sure this works.

If the repair is small, it's not too hard to simply scrape the sticky layer off.
 
lw395 said:
Not sure this works.

If the repair is small, it's not too hard to simply scrape the sticky layer off.
Click to expand...

Worst case if you time it right the overlay could be applied once the mix starts to cure and has gelled a bit - basically once it is firm enough that the application of (e.g.) clingfilm, will not push it out of place.

I'm going to give it a go on a bit of scrap and see if it works!
 
skyflyer said:
Worst case if you time it right the overlay could be applied once the mix starts to cure and has gelled a bit - basically once it is firm enough that the application of (e.g.) clingfilm, will not push it out of place.

I'm going to give it a go on a bit of scrap and see if it works!
Click to expand...
For small repairs I have watched HWMO use one of the plastic carbody repair kit mixer/applicator things, like a oversized credit card but smooth just like these https://www.fibreglassdirect.co.uk/plastic-applicators.html. or if you prefer white ones
https://www.amazon.co.uk/Polycraft-Body-Filler-Plastic-Spreaders/dp/B005F2VRSW
worked well on nearly flat surfaces only needing a gentle wipe with 1200 grit wet & dry then brasso.
 
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