Can anyone tell me of potential problems if I thin epoxy with alcohol. How much dna do you use? I haven’t tried heating epoxy yet, so I may try that first. My goal is to finally get rid of those damn air bubbles.
I was worried til I saw alcahol thinning w/dna sounded ripe
Here’s a link, but about West System epoxy, not RR.
http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html
JSS
That’s just what I need to see. I’m not using RR or West right now, but I am assuming that all epoxies suffer the same problems thinning with chemicals. I have been using Additive F in the epoxy I buy from US Composites. It did help with wet out (6oz S cloth) and got rid of a lot of the bubbles, I just need to get those last remaining stubborn ones. Will try the microwave and hairdrier on low on my next board. Should be Monday-Wed. Will post results.
Mahalo for the link.
i just throw in a little splash…probably about the same amount i put in as additive f
Aloha Puna Surf - I found that a cap full of dna is plenty. I also get some help if the epoxy sits for 5 min. before using. It heats up and thins way out. Shoots.
I would not add DNA to laminating epoxy… It makes it brittle and weak in my experience…
I have added it to epoxy just to thinly seal bamboo and balsa veneers, but this is just a sealing application not structural…
Warm up the epoxy or simply buy a lower viscosity resin system. There are high quality epoxy systems that have lower viscosities than the normal stuff surfboard builders use…
RTM and infusion systems are generally lower than average…
Ultimate air bubble remover : A vacuum bag
Speaking of bubble removers:
Here’s somethings I’ve done a couple of times with good results, and plan on revisiting again now that I do hot coats and finbox pours that “show”
I mix up my epoxy really well, I’ve always done that… When you do, you introduce lots of bubbles… I mix the resin be it K.K. or whatever in a non collapsable container, place this in a heavy duty freezer bag, Zip it up until 1/2" from one end of the zip lock and then place the vacuum hose into the bag and seal… Do not put the hose into the resin though!! Turn on the pump for a few minutes and watch those pesky bubbles dissappear If you start to pull the resin out of the container and into the bag, STOP…
I think scientists probably have special containers to do this professionally??
Also, a hair dryer passed carefully over a hot coat pulls those pesky bubbles up to the top of hot coats as well , where they pop and vanish… Be carefull trying this second trick though and only use if absolutely necessary…
Microwave the resin for 10 seconds.... then use a heat gun to pull the bubbles out after the hot coat is down.. If that doesn't work, then you might need to look at your laminating technique.
xylene from ace hardware or city mill
works just like Styrene as a thinner except for epoxy
wear a respirator
Xylene will affect the finished properties, but it is the thinner of choice (not DA); however don’t trade your bubble problem for different ones. A very few experienced glassers I know use xylene, but not regularly. They are very careful how much is added, and they’ve found this out the hard way. It’s not as forgiving as poly resin + styrene mixing. It’s a better option to address the bubbles as the others have said using a heat gun and stirring/lam technique.
what air bubbles
When the AST polyurethane resin was the rage a few years back, it was put in a vacuum pot first after catalyzing, it was unbelievable how much air got sucked into, then out of the resin before application to the board
DNA won’t effect EPS foam which is why we prefer it to Xylene. Xylene is fine under 3% but with DNA you can go to 5%+ without much problem. Most of the DNA in a laminate or hot coat will evaporate out during cure so it’s not really much of a strength issue when used sparingly. Having said that, heat works better … 10 - 15 seconds in a microwave, just the resin side before mixing, does a real nice job. BTW in my experience more bubbles can be introduced during laminating than during mixing. Be sure to follow general guidelines about overworking with the squeegee.