westerlylad
Member
Hi all. Anyone know the difference (if any) between these two products?
295i UV or 295 UV
- Thread starter westerlylad
- Start date
prv
Well-known member
Do you mean 291i? I don't think there is a 295i.
291i seems to have replaced 291 - I assume it's a slight reformulation. 291 is the "default" sikaflex for marine DIY, being a good sealant with some adhesive properties.
295UV is intended specifically for bonding in acrylic and polycarbonate windows, though it could be used for other things. 291 is officially not compatible with those materials, reacting with them to cause cracking (though I'm not sure how serious the problems are in practice). The 295 has a stronger bond - it's officially an adhesive which the 291 isn't, though I've certainly used the latter for plenty of non-structural sticking (instrument pods, pump mounts, etc). The name implies that it's more UV resistant, which would make sense for something used on windows. Most 291 is either inside, below the waterline, or at least inside a joint rather than in full sun.
Basically for most purposes I use 291 (which will now come as 291i). I don't know if I've ever used 295, though I'd consider it for more important bonding which needed more flexibility than epoxy - and if I ever found myself bonding in plastic windows since that's its raison d'etre.
Pete
291i seems to have replaced 291 - I assume it's a slight reformulation. 291 is the "default" sikaflex for marine DIY, being a good sealant with some adhesive properties.
295UV is intended specifically for bonding in acrylic and polycarbonate windows, though it could be used for other things. 291 is officially not compatible with those materials, reacting with them to cause cracking (though I'm not sure how serious the problems are in practice). The 295 has a stronger bond - it's officially an adhesive which the 291 isn't, though I've certainly used the latter for plenty of non-structural sticking (instrument pods, pump mounts, etc). The name implies that it's more UV resistant, which would make sense for something used on windows. Most 291 is either inside, below the waterline, or at least inside a joint rather than in full sun.
Basically for most purposes I use 291 (which will now come as 291i). I don't know if I've ever used 295, though I'd consider it for more important bonding which needed more flexibility than epoxy - and if I ever found myself bonding in plastic windows since that's its raison d'etre.
Pete
westerlylad
Member
HI prv, thanks for your reply. No I did mean 295i UV. I know it seems a bit odd, but if you google 295i UV you will get some hits. The stuff I am looking for is the adhesive/sealant intended for bonding perspex (acrylic) windows direct to gelcoat, with no other mechanical fixing, and there appears to be both Sikaflex 295 UV and Sikaflex 295i UV available on the internet. I just wondered if this was true and if, so, what the difference would be. I perhaps should direct my query to sika?
VicS
Well-known member
I think you will find that the Sikaflex you require may now be called Sikaflex®-295i UV
At least that's what it is called on the data sheet
https://boatoutfitters.s3.amazonaws.com/images/instructions/SikaFlex 295i UV Product Data Sheet.pdf
westerlylad
Member
Thanks VicS. Yes I've seen that datasheet too. But I can also find a similar one on Sika's own website which names the stuff as 295 UV. I think that the explanation may be that the USA version is 295i UV and the European version is 295 UV, but why there should be any difference in the name at all is still unclear to me.
prv
Well-known member
Ok - the Sika website I looked at didn’t list the 295i.
It sounds to me like a reformulation to either improve performance or comply with some safety or pollution regulation. It’ll be intended for the same job. You may find you can only get one or the other anyway - with the 291 for instance, I haven’t seen the non-“i“ version for sale for some years.
I think you’d need to contact Sika to find out more.
Pete
It sounds to me like a reformulation to either improve performance or comply with some safety or pollution regulation. It’ll be intended for the same job. You may find you can only get one or the other anyway - with the 291 for instance, I haven’t seen the non-“i“ version for sale for some years.
I think you’d need to contact Sika to find out more.
Pete
westerlylad
Member
Okay, thanks Pete. I've ordered some 295i from amazon. I'll try some experimentation with it to see if it sticks!
ip485
Well-known member
Something makes me think I came across the same when I replaced my acrylic - and one seemed to be the badge in the States. I came to the conclusion it was all the same product. Well worth the extra cost, but even then great care is required to ensure absolutely no weeping of the seals when you get a bluey dumped on the deck.
prv
Well-known member
Not quite the same application, perhaps - gluing acrylic on top of GRP rather than bonding glass into recessed aluminium - but this account might have some useful pointers:
Building Odyssey
When I read it years ago I took away the idea of rubber spacers to ensure a consistent and sufficient depth of adhesive - pushing down so hard that you squeeze most of it out of the joint is counterproductive
Pete
Building Odyssey
When I read it years ago I took away the idea of rubber spacers to ensure a consistent and sufficient depth of adhesive - pushing down so hard that you squeeze most of it out of the joint is counterproductive
Pete
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