When topsheets fail.. Help solve the mystery!

falls · Post by **falls** » Sun Jan 30, 2011 1:57 am

If you abrade the existing top (fibreglass) with sandpaper then you should be able to vacc bag a topsheet on top.
Is the new topsheet still ptex (UHMWPE)? Or something else.
You can just ride the board without a plastic topsheet if you want.

I have some of the natural ptex topsheet that is clear but not crystal clear that skibuilders stocked. No protective tape.
I can sell you some if you want, but am in Australia so there would be a bit of postage. I would have plenty for 3 snowboards if you wanted.

chrismp · Post by **chrismp** » Sun Jan 30, 2011 3:16 am

give it a couple polyurethane clear coats and you're good.

doughboyshredder · Post by **doughboyshredder** » Sun Jan 30, 2011 3:39 am

Crown does screw up sometime and send out material that isn't treated. They screwed up a whole run of green bases last year that I believe screwed a few people. This is one reason I flame treat all plastic immediately before layup.

Depending on your epoxy the importance of the ratios could be huge, or not. I have learned that QCM pretty much has to be exact. Your old epoxy may not need to be exact. The new epoxy may need to be.

This is also another good example of why we should all do test runs with any new materials before we layup a full board. (I've said this enough times, and not done it that I better next time, or it's going to burn me. AGAIN)

Second on the polyurethane clear coats.

Brazen · Post by **Brazen** » Sun Jan 30, 2011 9:15 am

I'm thinking the epoxy is the culprit.

doughboyshredder · Post by **doughboyshredder** » Sun Jan 30, 2011 9:27 am

Brazen wrote:I'm thinking the epoxy is the culprit.

except the old epoxy and new top sheet failed also, so the top sheet is not adhering regardless of epoxy used.

Brazen · Post by **Brazen** » Sun Jan 30, 2011 9:39 am

doughboyshredder wrote:
Brazen wrote:I'm thinking the epoxy is the culprit.
except the old epoxy and new top sheet failed also, so the top sheet is not adhering regardless of epoxy used.

True. I've never flamed topsheet before, but maybe treat a bit of that new stuff and try it again?

falls · Post by **falls** » Sun Jan 30, 2011 9:55 pm

I've sometimes wondered about the 'use by date' on flame treatment too.
I think the official word is to use stuff within 3 months of the treatment. I know my stuff seems to stick OK and has been sitting at my house for over a year. I then wonder how long it has been sitting at skibuilders before it is sold, and before that how long it has been sitting at Crown if it is an overrun.

I think the topsheet is the culprit - maybe it is a bit old, or maybe they forgot to flame it (as someone said this has happened before).
And the new epoxy doesn't sound ideal either.

rockaukum · Post by **rockaukum** » Wed Feb 02, 2011 7:33 am

I have been told by Crown that the overruns are re-treated prior to shipping. Have not had problems yet.
ra

kipi · Post by **kipi** » Wed Feb 02, 2011 5:54 pm

Thanks for all the answers

The polyurethane sounds interasting.. I have never used it b4
How do yo apply it as a topsheet?? can i have some information?

thx

chrismp · Post by **chrismp** » Wed Feb 02, 2011 11:14 pm

just spray, brush or roll it on

kipi · Post by **kipi** » Thu Feb 03, 2011 3:02 am

ok maybe I will try it

how many layers should i do??
what are the characteristics of this material ? why not just do a layer of epoxy for example?
how is it compared to p-tex TS??

does it get strached? what happens if it gets a strong hit?

some more ideas?!
Kipi

kipi · Post by **kipi** » Thu Feb 03, 2011 3:02 am

ok maybe I will try it

how many layers should i do??
what are the characteristics of this material ? why not just do a layer of epoxy for example?
how is it compared to p-tex TS??

does it get strached? what happens if it gets a strong hit?

some more ideas?!
Kipi

doughboyshredder · Post by **doughboyshredder** » Thu Feb 03, 2011 7:22 am

google

kipi · Post by **kipi** » Mon Feb 07, 2011 2:28 am

I have some questions about the polyurethane...

1. do i need to abrade the fiberglass/epoxy before coating with the polyurethane?

2. if i do abrade it, the epoxy loses his clearness and it turns dull... does it get clear again after wetted with the polyurethane?

3. if i brush the polyurethane, will there be marks?

tnx kipi

skidesmond · Post by **skidesmond** » Mon Feb 07, 2011 4:34 am

kipi wrote:I have some questions about the polyurethane...

1. do i need to abrade the fiberglass/epoxy before coating with the polyurethane?

2. if i do abrade it, the epoxy loses his clearness and it turns dull... does it get clear again after wetted with the polyurethane?

3. if i brush the polyurethane, will there be marks?

tnx kipi

Yes, you'll get better adhesion if you rough the surface w/ 120 sandpaper.
If you're going directly over the FG and epoxy you may get a little yellowing because oil based poly-u is not crystal clear. There are other types poly that might be more clear. Brush marks depends on the quality of poly and brush used. They usually level out pretty well.

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When topsheets fail.. Help solve the mystery!