Hey guys,
Today I took my second ski out of the press and it seems like I've really dded up...
When I had finished cutting out the excessive marterials at the sides of the ski i noticed that the topshhet layer had gone off the ski at the boders. The same thing happened with the base and the fibreglass layers.
So I started thinking and trying and came to conclusion that each layer can be teared off easily.
I have really no idea why, because I built the ski as my first one and the first ski doesn't make any problems...
The only thing that is different is that I've added a liquuid to reduce the air in the epoxy but it was about one drop of th air reducing liquid to a half kilo of epoxy(about 1.1 pounds). so I think that can't be the reason.
help me guys!! what went wrong??
here some pics...
ski layers don't bond together. what went wrong?!
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
ski layers don't bond together. what went wrong?!
Last edited by zeno on Tue Jan 05, 2010 11:13 am, edited 1 time in total.
-
twizzstyle
- Posts: 2204
- Joined: Tue Mar 07, 2006 8:25 pm
- Location: Kenmore, Wa USA
You added a "liquid" to your epoxy to help remove air?????
Please explain, what liquid did you add, and why did you add it?? You are using a pneumatic press, not vacuum bagging? You shouldn't need to do anything to the epoxy to get air out, it will squeeze out under pressure.
If that's the only thing you did differently, I think its pretty clear whatever this liquid is screwed your bond. But I'm really curious to know what the mystery liquid is...?
Please explain, what liquid did you add, and why did you add it?? You are using a pneumatic press, not vacuum bagging? You shouldn't need to do anything to the epoxy to get air out, it will squeeze out under pressure.
If that's the only thing you did differently, I think its pretty clear whatever this liquid is screwed your bond. But I'm really curious to know what the mystery liquid is...?
-
twizzstyle
- Posts: 2204
- Joined: Tue Mar 07, 2006 8:25 pm
- Location: Kenmore, Wa USA
Here is a working link sorry!!
http://picasaweb.google.com/zeno.sterz/Ski#
http://picasaweb.google.com/zeno.sterz/Ski#
-
twizzstyle
- Posts: 2204
- Joined: Tue Mar 07, 2006 8:25 pm
- Location: Kenmore, Wa USA
Hmm interesting. So where is it delaminating? Between your top sheet and graphics layer? Or is the fiberglass coming off of your core? I think its the latter, because you said the same thing happened with your base and fiberglass.
I'm very surprised that the additive you used would cause something like this, but it sounds like thats your only variable. Did you have problems with air in your epoxy in your first ski? I wouldn't use any additives like that unless you had problems.
Are you 100% sure you mixed the right ratio of resin/hardener, and mixed it well? Epoxy resin has to be spot on or you won't get a full cure. Polyester resins that just use catalyst don't matter, more catalyst means it will cure faster, less and it cures slower. But with epoxy resins, if the resin/hardener ratio is off even a little bit either way (too much or too little hardener) you won't get a complete cure/bond.
Did you do all the cleaning/prep the same on the second ski? Give everything a good wipe down with acetone before bonding?
Have you re-checked the first ski for the same delamination? I could be that it is just as prone to it it just hasn't started yet. Take a close look at the sides where you trimmed it off, see if you can pick any of the layers apart with your fingernail.
I'm very surprised that the additive you used would cause something like this, but it sounds like thats your only variable. Did you have problems with air in your epoxy in your first ski? I wouldn't use any additives like that unless you had problems.
Are you 100% sure you mixed the right ratio of resin/hardener, and mixed it well? Epoxy resin has to be spot on or you won't get a full cure. Polyester resins that just use catalyst don't matter, more catalyst means it will cure faster, less and it cures slower. But with epoxy resins, if the resin/hardener ratio is off even a little bit either way (too much or too little hardener) you won't get a complete cure/bond.
Did you do all the cleaning/prep the same on the second ski? Give everything a good wipe down with acetone before bonding?
Have you re-checked the first ski for the same delamination? I could be that it is just as prone to it it just hasn't started yet. Take a close look at the sides where you trimmed it off, see if you can pick any of the layers apart with your fingernail.