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09-21-2008, 01:28 PM
out of all the rapidsetting thinsets which has the most open time?

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09-21-2008, 01:58 PM
We use lots of it and it really seems to vary even within the brands. Tech and Hydroment have been very consistent for us..Customs had some hit and miss but I think it had a very good open time....sometimes too long. We use hydroment PM RS these days and like it..I keep a few bags of Lat.454 RS around for urgent repairs where I need expoxy like bond strength..But beware it goes off very fast.

I'm a big fan of the stuff in general.Anytime we have a question..if the house is gonna be cold and we're setting a large format floor..almost all our outdoor work gets rapid set..and all our glass over Kerdi is set with a modifed rapid set. It just eases my mind and i've had more than a few faliures that I would chalk up to insufficent cure(including latex migration months later)

09-21-2008, 02:21 PM
Welcome back, Trask. Nice to know the reports of your death were exagerated. :D

When you talk about that rapid set stuff going off quickly, how much time we talkin' about? Don't let the drill sit inna bucket while it slakes, or do you get to slake it and still have fifteen or twenty minutes to work with it?

I ain't never had the real need nor the juevos to try the stuff, myownself.

09-21-2008, 03:01 PM
I've tried Custom's Speedset and Mapei's Ultracontact RS. The Speedset was just about done in 15-20 minutes. The Ultracontact was about 30 minutes. I dunno who can use this stuff on a regular basis for big jobs. I'm just not that fast. But do keep some around for small jobs and for repairs.

CX, when you mix this stuff you just start burning it down. Slacking is not needed or required. The time estimates they give on the bag start from the time you add water ... just like SLC.

09-21-2008, 03:16 PM
It must be a regional thing. For us the fastest to slowest:

1. Custom
2. Mapei RS
3. Hydroment
4.. Laticrete

We once used a product in Miami called Jamo from HD. You couldn't get the mixer out of the bucket before it set off.

09-21-2008, 03:17 PM
seems you can get more time when you use colder mix water. generally, i get about 45 minutes set time. when new work was going more, the water was straight from the street(no heated water) and always quite cold. goda love that straight lake michigan water.


09-21-2008, 03:38 PM
I've found the water has a lot to do with how long it lasts. When I am doing a large amount (more than a few pieces) I like to use Hydroment mixed with latex instead of water. I've found that, depending on temp, it lasts two hours in the bucket and I can walk on it in less than three; it's very consistent.

09-21-2008, 04:53 PM
I think shelf life really has something to do with it too..Seems the longer the stuff sits the more unpredictable it becomes. We were having Customs speed set go off in an hour and then some in 10min. I dont think it was due to the bag contents being poorly distrubuted as I was dry blending it in the bucket before adding water.
I had one batch of Tec do the same thing..But it was pretty old. :rolleyes:

09-21-2008, 08:10 PM
The open time of Rapidset depends on what you are trying to do. 3 weeks ago I wanted to set 6 tiles so my plumber could get in and set the toilet, then I'd finish the rest of the floor with regular thinset. The stuff went off so fast I could barley get 3 tiles set and I had to mix a second batch.

Last week, I wanted to tape some backer early in the morning so I could Redgard it later, and get the floor set late in the afternnon. It was still soft 2 1/2 hours later.

I dont know, maybe I just dont use it enough to have a feel for it, but its totally unpredicatable to me.

09-21-2008, 08:24 PM
Geeeez, now y'all makin' me feel prudent rather than like a wimp. :D

09-22-2008, 02:16 PM
I have used customs speedset a lot, and it seems the fastest to me-- 30 min. or less. and i mix it a bit thin--
Latitcrete seems to give me 45 minutes or and doesn't get lumpy like the speedset.

I used some maepi once too and it was good for about and hour.
These times are working times....but the speedset takes an hour or two to walk on and the laticrete rapid takes longer. I love the stuff, and use it on most floors less the 100sf. to grout the same day.

Any body have a good homemade rapid set recipe? percent of calcium to thinset?