Gypsum plaster cracks while drying

[Trafikverket1]

Thanks for all the answers!

What gypsum plaster would you recommend that is actually gypsum plaster? I have some work left and might as well use the real stuff then.

At the risk of confusion as it seems I misunderstood gypsum plaster with gypsum filler (if plaster is supposed to be finicky, that is), but I think the one I linked to earlier is good, as is Dalapro DM60. I've also used Bostik Filler V28.

All of these have been similar, whether it's plaster or filler I'll leave aside. It becomes smooth, sands easily, is white, cures quickly and even in very thick layers.

 

[e02jr]

Edit: This was supposed to be a reply to MickeTyr, but I don't type fast enough.

This is not at all my experience with gypsum plaster.

I have plastered quite a few walls with the same brand from Hornbach and it has never been grainy. The only time it cracked where I patched thick was because it was poorly framed and drywalled, otherwise, it has been super stable. I probably haven't built 50mm at any time, but 30 without problems, without cracks, and with a completely even result immediately.

Isn't it an old bag you've got hold of? Has it perhaps been stored poorly?

 

[MickeTyr]

Edit: Would have been a reply to MickeTyr, but I don't type fast enough.

That is not at all my experience with gypsum plaster.

I have plastered quite a few walls with the same brand from Hornbach and it has never been gritty. The only time it cracked where I fixed it thickly was because it was poorly framed and plastered, otherwise it has been super stable. I probably never built 50mm sometime, but 30 without problems, without cracks and with an even finish right away.

Isn't it an old bag you've got? Maybe it has been stored poorly?

Really, strange. As far as I know, gypsum plaster contains some form of coarser particles, like sand or similar, whereas gypsum mortar/gypsum filler is completely free from this.

For example, from Finja's product description of gypsum plaster:

Composition
Grainy ballast, Additives, Calcium sulfate

I made the mistake of buying gypsum plaster instead of gypsum mortar on one occasion and quickly realized that it was completely different stuff when I started using it.

 

[paulssona]

With the risk of confusion as it seems I misunderstood plaster with filler (if plaster is supposed to be difficult that is), but I think the one I linked to before is good, as well as Dalapro DM60. Also used Bostik Filler v28.

All of these have been quite similar, so whether it's plaster or filler I'll leave aside. It becomes smooth, sands easily, is white, and cures quickly even in very thick layers.

Thanks for this. I bought Casco Wallfiller, a 300mm wide spatula, and fiberglass fabric that received good reviews. Still waiting for the stuff to dry, but by tomorrow morning it should be fully cured so the kitchen project can continue.

Big thanks to everyone. Don’t know if you need to 'close the thread' or something like that. But I feel really helped.

Have a nice late summer everyone.

 

[Twosunspots]

Suspect someone has been on your smygbräda. Have polished a lot of gipsputs and haven't seen anything like it?

 

[RichardRR]

Old thread but I have used the same? plaster/mortar from Hornbach for many projects and never had any problems. For example, when we were leveling the kitchen wall before installing the frames, we had plaster tracks that were 20-30mm and no cracks anywhere.
https://www.hornbach.se/p/gipsputs-baumit-25kg/7196557/

Could you perhaps have added too much water to the mortar?