is 1.2 mm base OK?

[jiri23]

Hello,

I could have a 1.2 mm base material for a really nice price. As I understand it most of you are using 1.3 mm material. Shold I expect some problems with the 1.2 material?

Thank you for a quick reply!

[MontuckyMadman]

You just need to find edges that fit for that size offset or be prepared to grind. You could end up with concave bases from uneven material = more grinding.
Its .1mm you'll probably be fine.

[doughboyshredder]

1.2, 1.3, 1.4 doesn't matter really.

As far as I can tell from unscientific testing if you are using a pneumatic press at a good high pressure (I am running at 70psi) and using dual heat controls the base becomes soft enough that there aren't any issues using the 1.3 or the 1.4, and the edge profile is 1.2 so that's fine.

[Dr. Delam]

I wouldn't use it unless your edge step is 1.2 mm. It's a pain in the ass dealing with concave bases and not worth the trouble no matter how much you save.

[jiri23]

I dont get the difference between 1.3 and 1.2 according the concave base. Do you mean with the 1.2 you dont have any acces material at the edge to grind off to get a flat base?

[sammer]

If the step on your edges is 1.3 and your base is 1.2 then your edges will be .1 mil proud and your base will be sunk in .1
It doesn't sound like a lot but...
The question in the back of my head is what are the tolerances in the base material and edges?
Now I'm gonna have to get out the micrometer and measure

I mean really, .1 of a millimeter is 4 thou of an inch.
Still a lot of grinding to get flat.
Once that is all pushed flat into your mold you might end up alright or you might have room for excess epoxy between your base and core.
depending on your pressure your core will flex convex.
.1 of a millimeter.


sam

[jiri23]

I am going to press my first pairs with vacuum so there will be no high pressure at all. I think i will give it a try - its € 100 for almost 30 m of 30 cm wide base. If the price € 12/m from boarbuildingsupply is a usual price then it should be a good deal?

[knightsofnii]

why not buy 1meter @ 12dollars a meter and test your theory out first?


Our new base which is on the way, is 1.2mm thickness, after subbing and flood coating it gains enough to mate to a 1.3-1.4 edge.

[jiri23]

the €12/m base is 1.3 mm so I cant even try it out. Anyway I have already bought the 1.2
Thanks for comments!

Hopefully I will have soon everything to start with layup. Now I am looking for some triax, resin and pretty much everything needed to vacuum layup except the pump.

[doughboyshredder]

If the step on your edges is 1.3 and your base is 1.2 then your edges will be .1 mil proud and your base will be sunk in .1
It doesn't sound like a lot but...
The question in the back of my head is what are the tolerances in the base material and edges?
Now I'm gonna have to get out the micrometer and measure

I mean really, .1 of a millimeter is 4 thou of an inch.
Still a lot of grinding to get flat.
Once that is all pushed flat into your mold you might end up alright or you might have room for excess epoxy between your base and core.
depending on your pressure your core will flex convex.
.1 of a millimeter.


sam

I kind of disagree.

1.2 is the stuff that crown is now making in china. It is cheaper and its purpose is for manufacturers that don't want to do much base finishing. Afaik it is all sanded on both sides.

1.4 is the standard thickness crown is making in the U.S. It's pretty much what every larger manufacturer is using for standard thickness allowing for more base finish work.

Not sure where the 1.3 comes in to play, although, I think it's the same stuff as the 1.2 with only one side sanded.

All I know is that I have built boards with all 3 and there is no discernible difference in the end product.

Standard cdw edge has a step of 1.3mm. I suppose that .1mm has to be made up somewhere, but with good pressure it shouldn't be an issue.

For manufacturing purposes, steel is a lot softer than ptex so grinding .1mm off the edge is quick.