stuartwineberg
Well-Known Member
The joint between the wheelhouse and deck has dried out and is leaking slightly. it needs scraping out and resealing from the outside - which version of sikaflex is the most suitable?
Which sikaflex?
- Thread starter stuartwineberg
- Start date
laika
Well-Known Member
291i
VicS
Well-Known Member
291 ( now 291i )
but see the users guide http://www.bluemoment.com/downloads/sikaflexusersguide.pdf
\Or consider one of the popular alternative such as CT1, PU40, or Stixall
but see the users guide http://www.bluemoment.com/downloads/sikaflexusersguide.pdf
\Or consider one of the popular alternative such as CT1, PU40, or Stixall
rogerthebodger
Well-Known Member
Or use the same product at non marine prices (sikaflex 221)
laika
Well-Known Member
Is it the *exact same product* with a different label cynically marketed or just close enough for many tasks?
I can buy 300ml of white 291i for a shade under a tenner at most chandlers. I can just walk off the boat a few hundred metres and buy it. Getting to somewhere which sells cheaper-but-probably-good-enough products is an enormous hassle and expense which for me at least (ymmv) really isn' worth it for a couple of quid on something which lasts months. Looking at google shopping I can't easily buy 221 mail order cheaper than I can get 291i from the chandler.
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stuartwineberg
Well-Known Member
Thanks Vics - so just to be sure, PU40 is identical stuff to the 291i? In that case the stuff builders use like Geocel the works would do and it is indeed a lot cheaper
Greenheart
Well-Known Member
I bought a 100ml tube of Sika 291 in 2013, believing it to be a powerful adhesive. I should have bought 292 - but I did the job with 291 and it held fast, despite its unsuitability.
Last year for about the same cost I bought a 300ml cartridge of 291i and used it to seal a new ply bulkhead onto GRP, plus transom ports. I'm very happy with the results, so I've bought another for several jobs this year. As has been said, at only a tenner in Force 4 for a decent-sized cartridge, it feels nice to have used a premium product.
Last year for about the same cost I bought a 300ml cartridge of 291i and used it to seal a new ply bulkhead onto GRP, plus transom ports. I'm very happy with the results, so I've bought another for several jobs this year. As has been said, at only a tenner in Force 4 for a decent-sized cartridge, it feels nice to have used a premium product.
VicS
Well-Known Member
PU 40 is a polyurethane sealant like Sikaflex 291. Geocel The Works is described as Scypolymer, but that's a trade mark. I suspect it's similar to CT1 or Stixall
vyv_cox
Well-Known Member
Having used PU40 extensively in UK and in Greece I find it pretty much impossible to tell one from another. One positive factor for PU40 is that it lasts far longer than Sikaflex once the tube is open. How this squares with a very similar cure time on application I do not know. I have recently bedded a new log/depth through hull fitting and some deck glands using a tube that was opened about this time last year. It is very viscous and needs a lot of hand pressure to squeeze it out but it is working fine.
I used clear Stixall to bed timber onto GRP on my motorsailer in UK. It has worked very well, some of the job being two years old with no sign of water penetration. Being clear it goes well with the varnished timber, almost invisible.
I used clear Stixall to bed timber onto GRP on my motorsailer in UK. It has worked very well, some of the job being two years old with no sign of water penetration. Being clear it goes well with the varnished timber, almost invisible.
antaris
Well-Known Member
We did the full length of the hull-deck seam of a friend's 35 footer with 291i TWICE this year and the thing will not set. Ever! It remains sticky and gummy and simply attracts dirt. We used two fresh tubes (hoping the first was a from a bad batch). I will be using alternate materials from now on. Have used it in the past years and it was great.
Tam Lin
Well-Known Member
That's funny, I had the same problem when sealing the new cockpit hatch I installed. Strangely enough the same tube was OK in other applications. I also found out something that I didn't know, Sikaflex has a best before date!
ghostlymoron
Well-Known Member
I've switched to Puraflex 40 (formerly PU 40) after reading Vyv's recommendation. Found it sticks and seals very well. Rather than sealing the nozzle with cling film after use, I just leave it with some sealant protruding. If using again within a few weeks, the protruding stuff can be grabbed with pliers and the plug of cured sealant pulled out. The sealant is then ready for re-use.
antaris
Well-Known Member
Both tubes used were well within their expiry dates - and from different batches and vendors. :ambivalence:
rogerthebodger
Well-Known Member
That was told to me my our local sikaflex rep who is employed by our local sikaflex office. It is also sold by my local chandler at a lower price.
Have a look here
http://www.uksealants.co.uk/sika-sealants-and-adhesives--c47.html
221 7.55 GBP or 5.55 GPB if you buy a box of 12
291i 8.99 GBP
Also have a look at the spec sheets of the 2 in the spec sheet for 221 it quotes " Fantastic in Marine Applications "
laika
Well-Known Member
£11.05 with the cheapest postage option, 11% more than I've paid for 291i in the past few years with a maximum 20 minute walk to get it, and if I bought 12 I think at least 10 would be past their best before I used them.
I don't have experience of 221. Doubtless it's perfectly good sealant indistinguishable from 291 for most things we might use it for and you're lucky to have such an exceptionally well stocked chandler nearby. I just question the notion (often expressed here) that people are idiots for buying 291. Once time and petrol/taxi fare/bus fare/postage have been factored in it's always been my cheapest option. Plus I *know* it'll work and how it'll work. Many people's options will be different. We don't all own houses and cars and hang out at specialist builder's merchants but most of us do muck about with boats and have a chandler somewhere handy.
ghostlymoron
Well-Known Member
http://www.toolstation.com/m/part.html?p=85566
Four quid a pop, marine industry, no minimum quantity.
PS I don't have any connection with TS
Four quid a pop, marine industry, no minimum quantity.
PS I don't have any connection with TS
vyv_cox
Well-Known Member
Was it previously sealed with a silicone sealant? Silicones inhibit the curing of a whole range of different products, one of the reasons I never have it on the boat.
GrahamHR
Well-Known Member
Even very low levels of acidity retard the polyurethane forming reactions; maybe residual acidity in the cured silicone ?
