Which Sikaflex do you use?

Sikaflex is a polyurethane adhesive sealant quite different to silicone

Mark here is a good deal more to it than just a "good quality silicone"
There is acetic and non acetic cure, some have mould inhibitors and others are designed more for sealing than for bonding
Sikaflex is a brand but when most people say it what they are meaning is a Polyurethane, these are different again and have many different qualities and uses to the various silicones with superior elasticity and bonding abilities and also their fire rating abilities to name a few ( the Sikaflex brand also sell silicone)
Polyurethanes are used much more widely in the building and boat/ marine industry but that is not to say one is better than the other it is a case of selecting the most appropriate product for the job.

Cheers

The blokes above are right - there's a major difference between polyurethane and silicone - and there's a major difference between sealants and adhesives.
Some products are more sealant than adhesive, and some are more adhesive than sealant.

There's also a major difference between different brands performance.
Sikaflex is a premium brand, you pay more for it and get superior performance accordingly.

It pays to read the label carefully and look at the "recommended uses"; the temperature range that the product can handle; whether it will handle wet conditions; what strata the product will bond to; and whether it is recommended for indoor or outdoor use.

You then select the product according to your defined use, as regards the strata, the temperature range expected, whether the area is regularly wet, and whether you are using it indoors or outdoors.

Cheers, Ron.

Sika make a large range of sealants Silicones, Acrylics, Polyurethanes etc etc. Contact Sika for their recommendations to suit your particular application. Don't speak to the red and green, and don't clean down with Turps.
There are many other sealant manufacturers who can provide the correct generic sealant for your application Bostik, Parchem etc. Speak to the manufacturer, not the retailer.

Sikaflex holds Commodore firewalls in place! Not sure which grade of Sikaflex is used in that application.

Most very large vans/ and interstate pantechs are also glued together with similar products.
Gotta use the right one in the right situation though.

Silicon is a whole different story as mentioned above.

I agree. Call Sika. Explain your requirement & they will advise on the best product for the job.

I work in building / construction. I use their info line all the time. They are very helpful & will almost always come up with a solution.

Hi louwai.
Thanks for your confirmation of my opinion ! Bought a new box trailer at least 30 yrs ago, thought I would seal the edges/corners where water could get into the folds. Spoke to the sika people, followed their advice,and it's still sealed and watertight.The trailer has done thousands of km's and has always lived outside.
Some years ago I had to replace a rusted out 2000 gallon water tank, did the usual search around, all quotes very similar, but the firm that I went with were the ones who asked where the water was coming from, ie,off the roof or pumped up (from a dam, well, etc ). Why ? said I ? He told me the reason. If we were taking water only from the roof , then he would use silicone for all the joins, NOT SOLDER. Were we taking water from any source using a pump, then all joins would be soldered. Aparently, vibration, over time, causes silicone to loose adhesion from one or other of the surfaces.
I've tried this theory on tool boxes mounted under the truck trays, and silicone sealing always leaked. Went to Neoprene 303 and never had a leak, so there you go !!!
Regards, string

Maybe. I used to be a roofer and we never used silcone as it ALWAYS when used with flashings pulled off one surface or another if there was any movement.

Between two dissimilar surfaces it isnt good at all.

We used stuff called Secomastic of which there is a Sikaflex equivalent.

It never set and allowed movement without losing its adhesiveness. I would go for a Sikaflex adhesive and a filler for the other kob.

If you use the wrong one for the job you will be unhappy with it but it may not be the products fault

Tom

At least you have an alternative .
I will try Secomatic next time , hopefully it is better than Sikaflex.

Cheers

Have used dozens of tubes of sikaflex when working in mates boat yard. Glued, stuck and held everything together. Old mate wouldn,t allow silicon onto the site. Reckoned it was garbage and sikaflex was the only thing to use when a watertight seal was reqd. I know some silicons actually eat guttering and roofing metals.

Mark you probably used the wrong one for the job or did not prepare the surfaces correctly . Sikaflex is a highly respected brand in its respective industries
It is no different to choosing the paint or the right oil for the job ....oils ain't oils lol sorry I couldn't resist that one

Alby,
maybe one of the reasons for choosing polyurethane over silicone is, one it can be painted over and two it has a higher bond strength + a little thing that lloyds of London used to guarantee the use of polyurethane blow the waterline, where they wouldn't guarantee the use of silicone.

I must agree silicon has it's place but not where paint is involved. I know they have paintable silicons but I would like to see the spec sheet on them.

Which Sikaflex product are claiming isn't UV resistant?
I have spent most of my life in the marine industry & all the Sikaflex products that we use have excellent UV resistance!

Maybe I got mixed up with it being non paintable.

I used sikaflex around my pool 3 years ago and its shrunk and going powdery, maybe I used the wrong one, I'll try Soudal on it next time as I use it for roofing and it's paintable and uv.

Some of the standard polyurethanes are effected by and will break down from chemical / chlorine attack. I have experienced the same issue myself
They do now make one specifically for pools

Most people that blame failure on a product have failed to read the instructions, I have known plenty who have blamed Sikaflex products but when asked if they used the primer, the standard response is "what primer"!
I also have a silicone ban for both vehicle & camper for the reason that you mentioned.

I don't think you would get any of the silicone manufactures to agree with your statement

Ably

Fair enough
I must have to much time on my hands to be still bloging about this subject
I think I may need to get a life

Cheers

Hahaha yeah, maybe he should just use sticky tape instead...........now which tape should he use LOL

You won't get too far out to sea in your boat, if you try to make underwater repairs with silicone! A few sailors have made that mistake, and paid for it with their lives!
Read about one bloke who was convinced "bathroom and tile silicone" was entirely satisfactory for hull repairs, because it was designed for wet surfaces! He isn't with us any more, thanks to that major decision-making error!

Cheers, Ron.

Can't believe someone can be so passionate about something so stupid and trivial as silicone adhesive..... It is a sad sad world.

Btw most use silicone because it is cheap and lasts long enough to not get come backs whilst in a warrant period and in most cases they don't know any differant.

We only use Sikaflex products as do many others I know in industry or who want to provide there customers with one of the best adhesive products around.

And I don't use it because I have a personel relationship with it and feel the need to protct the product , it's integraty or name....... i use it because it works very very well and does what it says it will do.

Real men use Sikaflex and Bolts/screws and the others use silicone and nails.

People have to understand silicone based adhesives have very limited applications whereby Sikaflex produces a range of specialised adhesives for a specific application.

Yep,
someone was passionate and stupid about using silicon sealant on the Sydney Opera House glass walls.

Those little panes of glass are 18mm thick and expand and contract a huge amount over the year.

That same silicon is still there 45 years later, guess it doesn't last very long in the sun or where expansion and contraction is involved.

Everything has a place for it's use and sika also make silicon products.

Real men pick the best sealant adhesive for the job at hand and sometimes that is liquid nails.