Sbr mix for dubbing out.

[hail hail]

Have a job on and need to dub out some ridiculously thick heavy parts before can get a scratch on it and going to use SBR. What ratio of sbr would you add to the mix. Reason asking is don't use SBR often and forgot how much one puts into the mix.

 

[Olican]

Whatever @Rigsby says is what I'd do

 

[Rigsby]

Usually there a ratio’s on the label. I did one for dubbing out at 1 part sbr to 3 parts water using washed Plastering sand and cement no other additives. It was very creamy and it was Everbuild sbr. Let it fully cure.

I also in the last coat added 10mm fibreglass strands.

 

[hail hail]

Usually there a ratio’s on the label. I did one for dubbing out at 1 part sbr to 3 parts water using washed Plastering sand and cement no other additives. It was very creamy and it was Everbuild sbr. Let it fully cure.

I also in the last coat added 10mm fibreglass strands.

If I remember right, going by the label on the back for a mix it was heavy use. Think it's 55 euro a tub here for silka sbr. Will get it again and have a crack at it.

 

[Rigsby]

Sbr can be expensive by the 5ltr. I bought it in 25ltr tubs for £50 net off r&j.

 

[brimplas1]

I love using renovating plaster for that, holds its own weight better than sand and cement and stiffens quicker also ... I've built up 3" thick reveals before in one day.....

 

[bobski]

Sbr mixes generally slump a bit more than standard plasticised mixes.

It's because it is basically a latex.

I'd do more layers thinner and build up - weaker mixes as you get to the final coats, if you definitely want to use it.