Which sikaflex variant

[RickS]

There seems to be a bewildering variety of Sikaflex product numbers so thought I'd ask.

The jobs i want it for are:

I am screwing a metal bracket to the wooden cratch board and need adhesive/sealant underneath

Also fixing solar panel brackets and cable gland to the roof so need good seal there too.

I have been told Sikaflex 291i will be suitable for all these jobs but wanted to be sure, hence the post

Thanks for all/any advice

[Quattrodave]

Yup i'd use 291i, 292i is also very good and stronger IIRC...

Edited April 26 by Quattrodave

[Clanky]

I used 522 to stick down the solar panel on the roof of my motorhome and it’s still there after several thousand miles to Europe and back many times 😁

[GUMPY]

Call sikaflex technical tell them what you want to do and ask them which one.

Their tech help desk is incredibly helpful.

[Peugeot 106]

Sikaflex EBT from Screwfix and builders merchants is quite a bit cheaper and readily available in black, white, brown or clear.  It’s not marine approved but a Narrowboat on canals doesn’t really qualify as marine. (Marine generally means suitability for saltwater eg A4 stainless rather than A2)

 

[Sea Dog]

Stixall is an alternative you might wish to consider. My solar panel brackets are bonded to the roof with it. Even with a very small footprint, they've survived everything the British weather can throw at them. Have a look at the many good  properties via Google but, notably, it's not silicone, so you can paint it if needs be.

[RAP]

OB1 or CT1. CT1 is marginally better, but of course both products are excellent.

[blackrose]

Yes there are other modified polymer alternatives to sikaflex these days and they're just as good and readily available in outlets like Screwfix.

 

Stixall, CT1, Sticks like Sh*t and The Dog's Bollox (I kid you not!). They're all really good and I think they're all available in clear which really helps with the clean up.

 

Key both mating surfaces first, wipe over with a dab of white spirit on a clean cloth and bed your metal to the wood with the sealant/adhesive. Clean up with white spirit or wet wipes before the sealant/adhesive goes off.

 

 

[john.k]

Yes ,dont try to remove anything stuck down.............on powerboats ,using sikaflex between skeg and glass hull would result in a big piece broken out of the hull when the prop hit something.

[GUMPY]

Preparation is the key.

Various caravan manufacturers stick the windows in with Sikaflex, one in particular skimps on the prep, not leaving it long enough after the pre treatment for it to cure. The result after a while is leaky windows and damp in the van.

There are pre treatments for Sikaflex that you should use if you want a good joint.

 

[Tony Brooks]

12 hours ago, blackrose said:

wipe over with a dab of white spirit on a clean cloth and bed your metal to the wood with the sealant/adhesive

 

I am not sure the white spirit is such a good idea, it does not evaporate particularly well at ambient temperatures s you could be applying the adhesive to a film of white spirit. Maybe that will be OK, but I would not risk it. I think I would use spirit wipe/panel wipe that evaporates readily.

[GUMPY]

Sikaflex make a cleaner and catalyst, Sika Activator 205, which surprisingly works very well. There is a different activator/cleaner depending on which Sikaflex you are using and the structure to be bonded.

 

[RickS]

Thank you everyone. Lots of good advice and plenty for me to think about, particularly in the preparation which I know I don't do as thoroughly as I should.

[blackrose]

On 27/04/2024 at 10:10, Tony Brooks said:

 

I am not sure the white spirit is such a good idea, it does not evaporate particularly well at ambient temperatures s you could be applying the adhesive to a film of white spirit. Maybe that will be OK, but I would not risk it. I think I would use spirit wipe/panel wipe that evaporates readily.

 

Since white spirit cleans up all of these sealants before they go off whatever tiny amount of reside is left is taken up by the sealant and isn't a problem. I've never had any issues doing it anyway and I've used these sealants a lot. I've attached plywood to steel as a mounting pad instead of drilling into the steel and once the sealant has cured you'd need a hammer and chisel to remove the ply.

 

Spirit wipes and panel wipes may evaporate but they will also leave residues. You need to remove any grease, oils and the dust created when you keyed the surfaces before applying the product, so whether it's a dab of white spirit on a cloth or a panel wipe take your pick.

Edited April 28 by blackrose

[Peugeot 106]

44 minutes ago, blackrose said:

 

Since white spirit cleans up all of these sealants before they go off whatever tiny amount of reside is left is taken up by the sealant and isn't a problem. I've never had any issues doing it anyway and I've used these sealants a lot. I've attached plywood to steel as a mounting pad instead of drilling into the steel and once the sealant has cured you'd need a hammer and chisel to remove the ply.

 

Spirit wipes and panel wipes may evaporate but they will also leave residues. You need to remove any grease, oils and the dust created when you keyed the surfaces before applying the product, so whether it's a dab of white spirit on a cloth or a panel wipe take your pick.

The obvious thing to do is to ring Sika helpline and ask them. 

[GUMPY]

1 minute ago, Peugeot 106 said:

The obvious thing to do is to ring Sika helpline and ask them. 

Is there an echo in here 🤣

[blackrose]

1 hour ago, Peugeot 106 said:

The obvious thing to do is to ring Sika helpline and ask them. 

 

Yes, I'll be interested to hear what they tell you.

[GUMPY]

Reply from Sika last year when I contacted them about bonding brushed alloy to painted alloy.

 

 

Hello Julian,

 

Thank you for your call earlier and interest in the Sika product range.

 

I enclose the pre-treatment chart for use with the Sikaflex-500 series products. Once you have found the correct substrate I recommend selecting the pre-treatment option from the blue (level 2) column.

 

The pre treatment chart is based on best current knowledge only and it is always recommended to apply a bead using the chosen pre-treatment onto the substrate to check the bond is good before using on the installation.

 

Always read the PDS’s, SDS’s the pre treatment guide before use since they contain important information and advice.

 

I enclose links where the PDS’s and SDS’s can be located.

 

https://gbr.sika.com/en/industry/transportation/pre-treatments.html

 

https://gbr.sika.com/en/industry/transportation/caravan-and-motorhomes.html

 

Pre-treatment-Chart-STP-Sikaflex-500-series-EN-CORP-05-2017-V6 (13).pdf

 

Edited April 29 by GUMPY

[Sea Dog]

56 minutes ago, GUMPY said:

Reply from Sika last year when I contacted them about bonding brushed alloy to painted alloy....

 

This seems to be a simple job getting quite complex!

 

Several years ago I stuck the (1 sq in) brushed alloy brackets for my solar panels to my painted roof with clear Stixall. No massive deliberation or discussion, no contact with the manufacturer, no pre-treatment, no mess, just a very quick rub with sandpaper and a wipe with white spirit and that was that. They're still there. 

 

[Peugeot 106]

10 hours ago, GUMPY said:

Is there an echo in here 🤣

Great minds think alike! I’ve always degreased with acetone or panel wipe ( I’ve done a lot of epoxy work) but although I have contacted Sika in the past I have never confirmed that acetone is a suitable degreaser for Sika. For anyone interested white spirit/turps are definitely a no no for epoxy. You do have to be careful if you want a maximum strength bond with all the various adhesives

[BWM]

11 hours ago, blackrose said:

 

Since white spirit cleans up all of these sealants before they go off whatever tiny amount of reside is left is taken up by the sealant and isn't a problem. I've never had any issues doing it anyway and I've used these sealants a lot. I've attached plywood to steel as a mounting pad instead of drilling into the steel and once the sealant has cured you'd need a hammer and chisel to remove the ply.

 

Spirit wipes and panel wipes may evaporate but they will also leave residues. You need to remove any grease, oils and the dust created when you keyed the surfaces before applying the product, so whether it's a dab of white spirit on a cloth or a panel wipe take your pick.

If the purpose is to remove a greasy or oily residue, then white spirit is the last thing to use!

[GUMPY]

40 minutes ago, Sea Dog said:

This seems to be a simple job getting quite complex!

Depends if you want it to stay fixed or not.

I was bonding a solar panel to the top of the caravan so 60mph winds are common. Didn't want it lifting off and hitting the car behind 😱

[TheBiscuits]

17 minutes ago, BWM said:

If the purpose is to remove a greasy or oily residue, then white spirit is the last thing to use!

 

Ambiguous.  Do you mean "use it for the final wipe" or do you mean "don't use it at all?" 😁

[blackrose]

37 minutes ago, BWM said:

If the purpose is to remove a greasy or oily residue, then white spirit is the last thing to use!

 

I disagree, it's always worked for me. White spirit removes any grease or oil and doesn't leave any significant residue itself - at least none that would present any issue with most single part paints or modified polymer sealants from sticking. I wasn't talking about pouring the stuff on.

 

44 minutes ago, Peugeot 106 said:

Great minds think alike! I’ve always degreased with acetone or panel wipe ( I’ve done a lot of epoxy work) but although I have contacted Sika in the past I have never confirmed that acetone is a suitable degreaser for Sika. For anyone interested white spirit/turps are definitely a no no for epoxy. You do have to be careful if you want a maximum strength bond with all the various adhesives

 

Agreed, I wouldn't use white spirit to wipe over before applying epoxy, but I have used the correct thinners for the epoxy. Likewise for single part paints based on white spirit thinners I've used white spirit as a wipe.

 

Doesn't acetone leave a residue too? 

Edited April 29 by blackrose

[Sea Dog]

35 minutes ago, GUMPY said:

Depends if you want it to stay fixed or not.

I was bonding a solar panel to the top of the caravan so 60mph winds are common. Didn't want it lifting off and hitting the car behind 😱

That's fair enough. We're not doing that here though, and experience on narrowboat roof mounted solar panels through several British winters seems a pretty fair test for the OP's similar application.