Yet Another Sikaflex (Or Similar Product) Question

[alan_fincher]

One of the regular recommendations for a sealant that isn't silicone based is Sikaflex.

However there seem to be countless types, and online descriptions don't make the differences particularly clear.

My immediate need is to re-bond some hardwood hatch surrounds to the steel roof of the boat, once I have taken it apart and de-rusted underneath it.  These are subjected to the rain run off from the roof, so the seal needs to be a very good one.

Do people have a specific recommendation to use for this type of application, please?  If Sikaflex, then which type, please?

I stress I want to avoid a silicone based product.

If someone can come up with something readily available in a Screwfix or Toolsstaton that would be great, as I really need it now, rather than having to do on-line ordering.

 

Ta.

[peterboat]

When I get back to the boat I will get you the name of some stuff I used to glue the brackets of the solar panels down, to say its strong is putting it lightly! I use tec screws as well but had a play with it just for fun and s**t to a blanket is the expression for the stuff

[Nightwatch]

Alan, like you, am confused about Sikaflex. I understood it to be ideal for windowinstallation as it remains flexible, so that windows con be removed. If sikaflex can be used for the application you describe above, then surely if it's load bearing in any way then the flexibility will be a disadvantage.

 

I have just used sikaflex to reinstall my mushroom vents after a scrape, derust and paint. But as mushroom vents have four retaining screws to hold them in place flexibility is a good thing. I'm bound to have to do it again as I am me! 

I will watch with interest.

[Chewbacka]

36 minutes ago, Nightwatch said:

Alan, like you, am confused about Sikaflex. I understood it to be ideal for windowinstallation as it remains flexible, so that windows con be removed. If sikaflex can be used for the application you describe above, then surely if it's load bearing in any way then the flexibility will be a disadvantage.

 

I have just used sikaflex to reinstall my mushroom vents after a scrape, derust and paint. But as mushroom vents have four retaining screws to hold them in place flexibility is a good thing. I'm bound to have to do it again as I am me! 

I will watch with interest.

A bit of flex is often designed into a bond.  As an example most car windscreens are bonded with a pu adhesive which has a controlled bond thickness a a few mm.  This allows the car body to flex over bumps etc without cracking the glass.  Likewise the temperature and expansion coefficients are different for glass and steel, this difference being managed by the adhesive.  So in the op problem, wood and steel will expand vey differently with temp and humidity so I would use an adhesive with a bit of flex and bond thickness of say 5mm but if the bits of wood are very long it may be more than the bond can accommodate.  

Something like this.   

 

https://www.toolstation.com/shop/p60981

 

added - if the trims are short say less than 300mm you will probably be ok with a thinner bond.

Edited September 13, 2018 by Chewbacka

[starman]

I called at a local sailing marina after Sikaflex and they said they now use CT-1 instead for all their yacht work - has all the same virtues, paintable etc, and comes in a variety of colours. Like the 'proper' Sikaflex (not the cheap EBT version that Screwfix and the like sell) it's not readily available in the DIY sheds.

 

[blackrose]

Stixall from Toolstation is pretty good and cheaper than Sikafkex. I used to use Marineflex until I found Stixall. 

 

Key both surfaces to be bonded, wipe over with a bit of white spirit to remove any dust, etc. Put the two surfaces together, leave for about 24 hours and you won't get them apart again - at least not without a hammer and chisel.

 

It goes off like rubber, is waterproof and comes in white, black, grey or crystal clear. It's very good stuff and I'd never be without it on a boat. 

Edited September 13, 2018 by blackrose

[PaulJ]

Stixall is very good without doubt and I use it regulary. I still use Sikaflex 291 for anything outside and/or  important though. A few quid extra for a tube is still alot cheaper than the possible cost of any water damage-and as Chewbaca says-a good fat bead of the stuff ...

 

[blackrose]

I've never had any problems with stixall or Marineflex outside. All my windows are bedded in with marineflex and they've been that way for 13 years. 

 

I used Sikafkex when I used to work in a boatyard and never found out any better. Can't remember which ones we used. 

Edited September 13, 2018 by blackrose

[Bee]

I tend to use double sided adhesive foam tape for a lot of stuff these days, might not work in some really harsh applications but its quite tough stuff and easy to clean up.

[cuthound]

14 hours ago, Bee said:

I tend to use double sided adhesive foam tape for a lot of stuff these days, might not work in some really harsh applications but its quite tough stuff and easy to clean up.

 

Will it hold dummy rivets on? ?

[Bee]

Dunno, mine are pop riveted on.

[David Mack]

On 13/09/2018 at 16:38, blackrose said:

Stixall from Toolstation is pretty good and cheaper than Sikafkex. I used to use Marineflex until I found Stixall. 

 

Key both surfaces to be bonded, wipe over with a bit of white spirit to remove any dust, etc. Put the two surfaces together, leave for about 24 hours and you won't get them apart again - at least not without a hammer and chisel.

 

It goes off like rubber, is waterproof and comes in white, black, grey or crystal clear. It's very good stuff and I'd never be without it on a boat. 

But is it paintable?

[Graham Davis]

38 minutes ago, David Mack said:

But is it paintable?

It is.