Question on poly and Epoxy prices

[cgildea]

So Im pretty much over poly at this point. Ive been through 3 1/2 gallons of resin and about 15-20ft of csm and have nothing to show for it. I can literally pull it off in one piece like its a mold. Ive pre coated the wood with a few coats and then laid the csm down. Ive tried it just a layer of resin and immediately following up with csm and same thing. Ive sanded and wiped with acetone. Ive tried not sanding and no acetone and same result. Ive mixed it at .75% 1% 1.5% 2% and even tried 4% swinging for the fences lol. I got a quart of resin from the parts store and followed the directions and same result. It cures and just peels right. I dont know what else I can do.....

So with that being said who has the best price on epoxy resin. Lol, Im tired of wasting time and supplies

 

[Davetowz]

I get all my epoxy from us composites.

 

[tpenfield]

Sounds like something is not right, might not be the resin. How do you know epoxy will work?

 

[cgildea]

Sounds like something is not right, might not be the resin. How do you know epoxy will work?

I dont. But it seems alot more user friendly than poly at this point

 

[76SeaRay]

What wood are you using or are you putting it on old fiberglass or gelcoat? What temperature are you at when you glass? Are you using laminating resin or finishing resin? I have both Poly and Epoxy and find Poly easier since it seems to saturate fiberglass cloth easier. I use Epoxy for internal structural pieces where it won't be finished. I use Poly where I will be finishing in gelcoat. All my wood is new marine plywood and is not treated. I use 10 drops catalyst per ounce of Poly resin (per US Composites) or 1/8 ounce of catalyst per 16 ounces of Poly resin. I pre-wet the surface, pre-wet the fiberglass, lay the glass on and then finish wetting it out. I keep my shop at about 60 to 65 degrees continuously. I am at 25 gallons of resin so far on my project and working on 30 gallons towards the finish line. All of it has adhered great and the peanut butter is rock hard.

 

[jbcurt00]

Auto parts store resin doesn't likely turn over very fast, I'd suspect it's the MEKP that's old, it has a shorter shelf life then resin. Combined w not wetting out the CSM fully.

Precoat the wood ONCE w kicked resin & allow to tack up, but not cure, apply kicked resin to precoated wood & CSM, then transfer wet CSM to precoated wood, smooth & confirm sufficiently wetted.

FYI using 4% made non-stuck laminate problem worse by speeding up cure.

 

[cgildea]

What wood are you using or are you putting it on old fiberglass or gelcoat? What temperature are you at when you glass? Are you using laminating resin or finishing resin? I have both Poly and Epoxy and find Poly easier since it seems to saturate fiberglass cloth easier. I use Epoxy for internal structural pieces where it won't be finished. I use Poly where I will be finishing in gelcoat. All my wood is new marine plywood and is not treated. I use 10 drops catalyst per ounce of Poly resin (per US Composites) or 1/8 ounce of catalyst per 16 ounces of Poly resin. I pre-wet the surface, pre-wet the fiberglass, lay the glass on and then finish wetting it out. I keep my shop at about 60 to 65 degrees continuously. I am at 25 gallons of resin so far on my project and working on 30 gallons towards the finish line. All of it has adhered great and the peanut butter is rock hard.

Plywood sheathing from lowes. Its not treated. I havent been going by drops. Just going by percentage of volume of resin

 

[cgildea]

Do yall think its worth switching to the marine plywood to get a better bond than this pine plywood?

 

[kcassells]

its not the wood its the glue like @jbcurt says. That much non stick is a resin problem.
Where did you get the glue?

 

[76SeaRay]

Marine plywood is not necessary, more nice to have so you get better water resistance over the years. Agree with the above, it sounds like a resin or catalyst quality problem. I used US Composites poly but just got the last 5 gallons from Fiberglass Supply. US Comp is cheaper than Fiberglass Supply but being in Washington State, it came out cheaper due to shipping. Fiberglass Supply is in Burlington, Washington so driving distance for me.

 

[cgildea]

its not the wood its the glue like @jbcurt says. That much non stick is a resin problem.
Where did you get the glue?

I got it from a local supplier. Like I said though I even bought a quart from the parts house amd I had the same result. Kinda leads me to believe its more the wood than the resin?

 

[jbcurt00]

Try again on a small scrap piece of ply and using metric:
100ml resin
1.5ml MEKP
And follow steps above,

If not old resin/MEKP it appears that you CSM is resin starved, not fully wetted, which is common w novice glass work.

Pictures are helpful

 

[kcassells]

I got it from a local supplier. Like I said though I even bought a quart from the parts house amd I had the same result. Kinda leads me to believe its more the wood than the resin?

Glass/glue sticks to just about everything even bad wood if done properly. Like JB said. Seems like your process is right. So not trying to get you mad. Something in the application is wrong or the glue is bad. Last comment is how old is the glass? Did it get wet maybe?

 

[cgildea]

Try again on a small scrap piece of ply and using metric:
100ml resin
1.5ml MEKP
And follow steps above,

If not old resin/MEKP it appears that you CSM is resin starved, not fully wetted, which is common w novice glass work.

Pictures are helpful

I tried that, I did 1000ml of resin and 10ml mekp. Then went to 15ml mekp when first batch didnt work. I dont have many pictures from when i was doing it. I didnt want to get resin on my phone. Maybe this will help. This is some of the old pieces I pulled off. You can see some of it tried to stick. But its not sticking like it should

 

[cgildea]

Glass/glue sticks to just about everything even bad wood if done properly. Like JB said. Seems like your process is right. So not trying to get you mad. Something in the application is wrong or the glue is bad. Last comment is how old is the glass? Did it get wet maybe?

Im not sure how old it is. But I figured when I got the quart from the parts store it would be a fresh batch. I dont think the mat is resin starved. Its fully transparent and Im pushing off some excess resin as i roll it out with the grooved roller....

 

[jbcurt00]

Re-reading original post, the breakdown is somewhere in the details:

Tried good prep, failed to bond
Tried better prep, failed
Tried worse prep, failed
Modified MEKP ratio, failed

Appears to be wetted out, but are you wetting CSM before or after you lay it up.

As mentioned, it's extremely unlikely to be type of ply chosen. And unless stained, CSM is unlikely to be damaged. Perhaps humidity is a factor. CSM isnt at all damp? Already applied & prepped wood is washed/flushed well w acetone, not just a damp rag? Heavy on acetone may remove even the slightest hint of moisture due to humidity, but not for long in most of the US. It's nearly unbearable outside here today.

Moisture
Old resin
Old MEKP
Application error

But not ply choice
PreWet CSM before layup

 

[cgildea]

Re-reading original post, the breakdown is somewhere in the details:

Tried good prep, failed to bond
Tried better prep, failed
Tried worse prep, failed
Modified MEKP ratio, failed

Appears to be wetted out, but are you wetting CSM before or after you lay it up.

As mentioned, it's extremely unlikely to be type of ply chosen. And unless stained, CSM is unlikely to be damaged. Perhaps humidity is a factor. CSM isnt at all damp? Already applied & prepped wood is washed/flushed well w acetone, not just a damp rag? Heavy on acetone may remove even the slightest hint of moisture due to humidity, but not for long in most of the US. It's nearly unbearable outside here today.

Moisture
Old resin
Old MEKP
Application error

But not ply choice
PreWet CSM before layup

These were on different pieces of boards. It wasnt just a bunch of failed attempts on the same board. I have not tried wetting out the csm and then applying it. Seems like it would tear/fall apart while being moved. I dont see where it would be bad resin or mekp because I got a batch from the store and had the same results.

 

[Mad Props]

Im not sure how old it is. But I figured when I got the quart from the parts store it would be a fresh batch. I dont think the mat is resin starved. Its fully transparent and Im pushing off some excess resin as i roll it out with the grooved roller....

I think the "parts store" resin is the key here... if you mean autoparts store, then its most likely not laminating resin... it probably has the wax in it to fully cure so it can be sanded for body work...

Maybe I missed something, but that would be the smoking gun in my opinion...

As others said, the wood isn't your issue..

 

[proshadetree]

If in fact you are using waxed resin you must sand/ grind between coats. The wax layer floats to the top and will prevent a good bond without getting rid of it.

 

[cgildea]

Bought a small piece of pine 1x4 today from the store. Going to try it and see what happens. I made some extra and laid out some csm on the inside of my boat. Im thinking if it sticks to the boat and not the wood then Im doing something wrong with the wood.