Epoxy filling

[Dhlo12]

Hey Guys,

any recommendation of what epoxy product will be best to use for filling up a gab in between steel plates (12-15mm thick each) , the idea as to have it injected as the plates are welded together in one length of 10m .

 

[TugboatEng]

Belzona has a plate bonding procedure that resembles this exactly. The product they use is 5811. They did a video about it on their Belzona TV YouTube channel. I am looking for it now.

 

[epoxybot]

That is quite a large gap and many epoxies will generate a fairly high exothermic reaction at that thickness, resulting in either a large degree of shrinkage or even worse foaming. In order to inject the epoxy, you will want an epoxy with either a 1:1 or 2:1 ratio. Liquid epoxies will deliver higher bond and tensile strength, while paste/gel (filled) epoxies will provide higher compressive strengths..., generally. In the gel category, epoxies designed for segmental bridge bonding are long potlife, generally low exotherm prospects. Low exotherm, long potlife liquid epoxies are harder to find. Sika would certainly have the segmental bridge bonding adhesive/s. Chemco Systems will have liquid, gel and paste version of low exotherm, long potlife epoxies and the injection equipment for the job. Keep in mind that low exotherm and long potlife epoxies tend to have longer full-cure times and may require temperature conditions above 50F degrees.

 

[dik]

There may be problems with 'creep'. I recall the 'Big Dig' failure used a fast setting epoxy that had creep issues.

 

[Dhlo12]

Belzona has a plate bonding procedure that resembles this exactly. The product they use is 5811. They did a video about it on their Belzona TV YouTube channel. I am looking for it now.

We ended up going with Fosroc Lv injection, I am no quite confident with it

 

[TugboatEng]

Steel is one of the easier materials to bond with epoxy. The key is surface prep. Treat it as if you're applying any other durable coating.

 

[Dhlo12]

That is quite a large gap and many epoxies will generate a fairly high exothermic reaction at that thickness, resulting in either a large degree of shrinkage or even worse foaming. In order to inject the epoxy, you will want an epoxy with either a 1:1 or 2:1 ratio. Liquid epoxies will deliver higher bond and tensile strength, while paste/gel (filled) epoxies will provide higher compressive strengths..., generally. In the gel category, epoxies designed for segmental bridge bonding are long potlife, generally low exotherm prospects. Low exotherm, long potlife liquid epoxies are harder to find. Sika would certainly have the segmental bridge bonding adhesive/s. Chemco Systems will have liquid, gel and paste version of low exotherm, long potlife epoxies and the injection equipment for the job. Keep in mind that low exotherm and long potlife epoxies tend to have longer full-cure times and may require temperature conditions above 50F degrees.

if shrinkage is experienced, would you try replying/reinjecting an additional layer?

 

[TugboatEng]

No, the shrinkage gap would be too thin to push epoxy through reliably. Use epoxies that are 100% solids to minimize shrinkage. You're also relying on a secondary bond between the epoxy layers that may not be as strong as the epoxy to steel bond.

 

[Dhlo12]

But wouldn’t that be better that leaving a gap or air bubbles ? Or would that create creeping on the overplate?

 

[TugboatEng]

You need to control your application so that you do not have gaps or air bubbles. Creeping on the over plate can be removed with a grinder.

 

[Dhlo12]

You need to control your application so that you do not have gaps or air bubbles. Creeping on the over plate can be removed with a grinder.

copy that, many thanks