Immediate delamination

[Jack2048]

I had a similar issue when I started my project in which I started being alot more generous with the acetone and putting a coat of resin down prior to laying and wetting the cloth and it really eliminated that issue for me.

Interesting. Can you provide some details on what you actually did? And what do you mean "more generous"? The acetone evaps so quickly.

 

[kcassells]

Jack,
Whats your tech. for applying glass? What are your steps.

 

[Jack2048]

Jack,
Whats your tech. for applying glass? What are your steps.

• Angle grinder w/40 grit sanding disc to remove original fiberglass and gelcoat.
• Vacuum.
• Wipe down with acetone to make sure surface is clean, no remaining dust.
• Mix fresh poly
• apply poly with roller
• lay down glass
• apply poly with roller on glass
• remove airbubbles with fiberglass roller

 

[PC on the Bayou]

Just a guess, but how vigorously did you roll out the glass to make sure you didn't have an layer of poly between the old glass and new?

If I'm not clear on this, what I am poking at is that if you didn't roll out the glass vigorously to remove excess resin, then there could be a layer of too much resin between the old glass hull and the new glass mat. Resin itself isn't very strong, so what you could be seeing is the failure of the resin between layers.

The extra resin applied before the mat doesn't have anywhere to soak into like it does on the fresh new wood (i.e., transom).

Just a thought.

 

[Jack2048]

Just a guess, but how vigorously did you roll out the glass to make sure you didn't have an layer of poly between the old glass and new?

Yeah, missed a step. Used one of the fiberglass rollers used to remove the air bubbles.

If I'm not clear on this, what I am poking at is that if you didn't roll out the glass vigorously to remove excess resin, then there could be a layer

This is a great point. I do feel I was properly vigorous.

Resin itself isn't very strong, so what you could be seeing is the failure of the resin between layers.

I am leaning in this direction in that maybe I didn't get enough resin on the glass.

The extra resin applied before the mat doesn't have anywhere to soak into like it does on the fresh new wood (i.e., transom).

Right, to clarify, I rolled out the resin, and while still wet, put down the glass.

 

[kcassells]

• Angle grinder w/40 grit sanding disc to remove original fiberglass and gelcoat.
• Vacuum.
• Wipe down with acetone to make sure surface is clean, no remaining dust.
• Mix fresh poly
• apply poly with roller
• lay down glass
• apply poly with roller on glass
• remove airbubbles with fiberglass roller

Perfect. I just can't understand the delam at this point. So give it another shot. It appears not to be method or product.
Do a test patch in the same area and see if you get a bond.

 

[JASinIL2006]

The only thing I could really see that might be an issue is the wiping down with acetone. If there is any surface contamination, you really need to wash it down with acetone; wiping it with a cloth mildly dampened with acetone might not be enough. But even so, it's hard to imagine that would result in such a complete delamination. Very odd.

 

[tpenfield]

Does not look wetted out. The glass layer should be clear and you should be able to see through it.

 

[Jack2048]

The only thing I could really see that might be an issue is the wiping down with acetone. If there is any surface contamination, you really need to wash it down with acetone; wiping it with a cloth mildly dampened with acetone might not be enough. But even so, it's hard to imagine that would result in such a complete delamination. Very odd.

Ok, this is the second vote for "washing" with acetone.
It evaps so quickly, can you expand on this a bit?
Are you saying just to pour the acetone over the hull? Scrub it?

 

[Jack2048]

Does not look wetted out. The glass layer should be clear and you should be able to see through it.

Sure. It was clear as you mentioned. The photograph is from when I had already started to remove the glass. I had already pried it off the hull.

 

[88 Capri (2022 SOTY)]

Interesting. Can you provide some details on what you actually did? And what do you mean "more generous"? The acetone evaps so quickly.

I saturated the rag I was using almost like slopping it on and it would make the existing glass sticky.
I would apply a layer of resin just as I was about to lay the cloth down and pour a small puddle of resin and use a bristle brush and work towards the outside.
I also found that depending on temperature and humidity a little too much hardener would cause it to set to quickly not allowing the saturation for the bond.

 

[88 Capri (2022 SOTY)]

Yeah, missed a step. Used one of the fiberglass rollers used to remove the air bubbles.

This is a great point. I do feel I was properly vigorous.


I am leaning in this direction in that maybe I didn't get enough resin on the glass.


Right, to clarify, I rolled out the resin, and while still wet, put down the glass.

I personally had trouble with the roller method and went to the cheap bristle brushes.

 

[Jack2048]

I personally had trouble with the roller method and went to the cheap bristle brushes.

Boatworkstoday and fiberglasssite uses rollers. Someone here mentioned using squeegees, which I have seen epoxy guys use. I am going to try that.

 

[Jack2048]

I saturated the rag I was using almost like slopping it on and it would make the existing glass sticky.

Oh, interesting , learned something. Bought a gallon of acetone tonight. Will try your technique.

I would apply a layer of resin just as I was about to lay the cloth down and pour a small puddle of resin and use a bristle brush and work towards the outside.
I also found that depending on temperature and humidity a little too much hardener would cause it to set to quickly not allowing the saturation for the bond.

I tend to stay in the middle of the mix range so I have enough working time.

 

[JASinIL2006]

I saturated the rag I was using almost like slopping it on and it would make the existing glass sticky.
I would apply a layer of resin just as I was about to lay the cloth down and pour a small puddle of resin and use a bristle brush and work towards the outside.
I also found that depending on temperature and humidity a little too much hardener would cause it to set to quickly not allowing the saturation for the bond.

Yeah, I would soak the rag frequently, scrub the surface, then wipe with a clean cloth. Acetone is cheap compared to resin.

 

[Jack2048]

Yeah, I would soak the rag frequently, scrub the surface, then wipe with a clean cloth. Acetone is cheap compared to resin.

Got it. I wasn't nearly that aggressive.

 

[Jack2048]

Quick update. I ground off and removed all the problem glass, applied copious amounts of Acetone to the hull, and reapplied glass and poly. I am now getting proper adhesion. Though the hull never got gummy as had been mentioned. It had been mentioned to me, this may be due to age, 1994 hull.
I went to put on my respirator and it smelled of Acetone, time to replace the cartridges!

Thanks to all for the help!

 

[JASinIL2006]

Glad it worked out for you!