hand lay up of coracell m foam

impact testing is a waste of time... put the hammer away.... if you want to do tests, do bending tests not impact tests...

Looks like the glass was not wet out in that first pic... thick glass can be difficult to wetout, you need to put a wet coat of epoxy on the foam first and roll it into the surface of the foam to let it drink up what fills the surface of the foam (about 300grams per m^2) then pour some more epoxy over this before you lay your glass onto the wet resin (this wets out the underside of the glass) then pour more resin over the glass and spread it around lightly ( to wet the topside of the glass), Then start to roll it in until it goes completely transparent and the air bubbles are gone, no white strands...

it really isnt that hard????

 

Is the cloth turning semi-transparent as you squeegee it ? It should never remain white.

 

45 strands are very simple to lift off if the epoxy has not fully cured (for a week).

They will sometimes stick to peel ply at an edge and lift right off if you are not very careful.

What are you building anyway? 6oz cloth... 12oz cloth... those are not structural type laminates.

You have dry glass. You probably didn't use enough epoxy on under the glass.

 

Whoops - groper got in ahead of me - before i refreshed this page.

That last picture tells all. You are getting a good wetout, you are just being too destructive in your testing. If the strands of glass are pulling away from each other - you are being too destructive.

Gropers comments about impact testing apply. Don't smash it - jump up and down on it or apply heavy weighs.

 

the hammer test was after i had broken it from.........yup putting weights onit.sheesh a guy can't even test what happens when a hammer hits it..

so where were we.yes maybe after smashing it up so much (because this is my first go at it)the glass got pulled off?

after re checking my first test panel that had 2 layers of 6oz on one side,it appears to be stuck good probably cause the glass wetted out more easly.the 12oz seams to be a bit slower in taking the resin,next time i'll let it sit a bit and double check that its soaked all the way before i add more glass.


Cat i'm using 12oz biax 45 45 and 0-90 playing with layers of it.so far 24oz on each side is giving me the strength i was looking for.as for what i'm building is a 12' driftboat with a 48" wide floor light enough to put on my roof rack of my truck.at first it was going to be just interior parts but after some tests it may end up being the floor(hull) also.

again thanks for helping a newbie its been fun..

 

which is it???

 

Patchy cure and things not sticking !!
Foam has to have resin on the surface !! a good wet out and dont miss any where including the edges !! its not just run a semi dry roller over the top and hope for the best . !!
Patchy cure is resin and hardener not mixed properly . drop a couple of drops of a color of some sort in the mix if its not mixed it will look streaky !! mix and let stand for a minute or two then mix again !!!
Personally i would drop those squeerge in the bin !! they are more trouble than they are worth !! if you apply differant pressure you leave differant amounts of resin behind or if you press harder you take to much out of the glass and it starves !! thats another possible reason for things not going off or not sticking properly . I can and do make a much better and absolutly trouble free job with a 4 or 6 inch paint roller and roll the peel ply at the same time and never have to worry ever .
You cant Re using peel ply !!!!How do you get the resin to come up through the weave of the peelply to the top surface ??dont you understand what its there for ?? damn theres some thick people around !!

 

patchy cure ???? Re-use of peeply ?? Where did that come from ?

Tunnels must have dropped something heavy on his foot again - all the rest of the world is so thick !

 

you should probably re read what i had posted,if your referring to my post.

 

ya i kinda didn't no what to say,maybe its a holiday over there hic!!

 

I cant believe the problems you guys have doing a simple straight forward job of wetting out and applying glass to things . Bubbles hard to get rid of !! pricking the bubble !!! come on dont you use a hard roller ?? what about wetting the surface and making sure its really wet then peel ply and steel roller it !!! , is it to hard ??

I must go read the pictures in another chinese kids book its to much for me !!
Yes i had a bad weekend and very little sleep !!.

 

Let me rephrase, thick glass can be difficult for inexperienced people to wet out... you need enough worked into the surface of the foam so the glass doesnt wick the surface of the foam dry, then you need enough in the glass so its transparent, then dont pull too much out with the squeegee when your finishing it off...

 

thanks groper ,i wonder if i'm over squeegeeing haha is that even a word?

 

maybe you could be a little more specific about this "peelply" i went to the local lumberyard and asked for peel plywood they didn't no what i was talking about??

 

i heard this the other day,
x

There are two big conferences in NY, one for construction engineers and one for lawyers. They are both being held in the same building downtown.

On the first day of the conference, two groups run into each other at the train station and chat while waiting in line to buy tickets into the city.

When they reach the counter, the three lawyers each buy tickets and watch as the three Engineers buy only a single ticket.

"How are three people going to travel on only one ticket?" asks a lawyer. "Watch and you'll see," answers an Engineer.

They all board the train. The lawyers take their respective seats, but all three Engineers cram into a restroom and close the door behind them.

Shortly after the train has departed, the conductor comes around collecting tickets. He knocks on the restroom door and says, "Ticket, please."

The door opens just a crack and a single arm emerges with a ticket in hand. The conductor takes it and moves on.

The lawyers see this and agree it is quite a clever idea.

After the conference, the lawyers (recognizing the engineers' superior intellect) decide to copy the construction engineers on the return trip and save some money . When they get to the station, they buy a single ticket for the return trip.

To their astonishment, the construction engineers don't buy a ticket at all. "How are you going to travel without a ticket?" says one perplexed lawyer. "Watch and you'll see," answers an engineer.

When they board the train the three lawyers cram into a restroom and the three construction engineers cram into another one nearby. The train departs.

Shortly afterward, one of the construction engineers leaves his restroom and walks over to the restroom where the lawyers are hiding. He knocks on the door and says, "Ticket, please."