Hello so I just finished shaping my first board and where and I want to get started on sealing it before I glass it. Is there a recommend temperature to seal. Also when I do seal it can I have it sit for awhile before I glass it, it’s still not hot enough for me to glass the board. Any advice is helpful thank you
Hello Joel1, welcome to the forum.
What material is the board (wood, EPS, PU foam)?
What material(s) are you using to seal and glass (epoxy, PE resin, fiberglass cloth)?
It is eps, I have Q cell and resin mix, to seal it
Here is my 2 cents, it may be worth even less than that…
There is a point, say 15 C 60 F where some 2:1 clear epoxies will slow down to a crawl or stop curing altogether. Some manufacturers will disclose this, some will just say warmer is better and send you on your way. There are some 3:1 or 4:1 formulations that can cure in lower temps but come with the downfalls of amine blush and tints that don’t play well with color work or bright white boards.
The technical data sheet for the epoxy will give a temp where viscosity and cure times are measured, this would be the ‘recommended’ temp. Above this temp and the reactions can happen faster, making glassing ‘exciting’ to having a pot of resin go exothermic and turn burn-your-hand hot and rock hard in a matter of minutes.
Doing the Q-Cell and resin way before you plan on glassing makes for having to sand and a mechanical bond between the two operations rather than a chemical one. Ideally each layer of epoxy is added to the previous during its no-sand, chemically bonding window which can be like 1-3 days depending on brand and temp with higher temps curing out the resin sooner. I am not a Q-Cell person, I imagine there is a little sanding to be done after it’s applied so that step may happen anyways.
Another tip is to coat/glass when the board is slightly warmer than the surrounding air to minimize ‘outgassing’ of the blank.
I gotcha and one other quick question, so colder weather is coming up in the week where I live but tomorrow is supposed to be 77 should I try to do all glassing tomorrow or should I wait until it’s constantly in the 70’s?
I would wait for the board if possible, between Q-cell filling top and bottom and glassing top and bottom that is 3 flips and a lot to manage in one day, especially if it is a first time for everything and the resin is not setting up quickly. You could make a test piece of EPS to fill and glass one side to mess around with tomorrow and see how it goes.
Will do thank you for the advice
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50%Qcell 50%resin, warm everything, blank and resin around 20°C and keep this temperature first couple hours when resin set to avoid blush. Seal well everywhere better more than less. Let fully cure and sand.
I made epoxy board fore 32 years try all kind of way to go, sealing eps foam is one key to do it right. All work after a good seal will be easier and better. Do it like you want (resin, mastic, spackle, etc…) but do it right.
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Yes sealing the blank is key. Early on after 2007 a lot of EPS blanks started showing up in the glass shops on Maui. One glasser I knew just brushed a coat of straight Epoxy on the blank with no Q-cell. Both sides the night before he would laminate. Kind of a minimalist approach, but it worked for him. Mostly sealing the blank falls into two methods; 1. Epoxy resin with a thickener added. Or 2. Water based Spackel, thinned with distilled water or Acrylic sealer.
Alright so I tried to seal it using resin and Q cell but it’s not drying, is there a way to remove it or should I just hope it drys and go from there. what is the best course of action form here I’m thinking it would better to use spackle but little lost in what to do next
Which epoxy? Properly measured and mixed? How long ago? What temp?
If you have one of the slower setting varieties, it may take some hours for it to cure enough to be non-tacky and then some more to be sandable.
You mentioned having a weather window, I would keep the board as warm and dry as possible and it should eventually cure to the point of being able to be sanded.
I have not had good results with spackle+acrylic, it got sort of rubbery and balled up during sanding. Not saying it cannot work but it just didn’t for me.
I used green room epoxy I applied it Saturday it was 77 degrees Fahrenheit then, I did the correct measurements for the mix, yesterday was in the 60’s today is in the 50’s. Should I get a soace heater and try to heat the room up?
Warming up the room or bringing the board somewhere warmer would be good, both for curing and to reduce blush.
-Did the cup you used to mix cure out OK?
-Does the board seem wet, sticky, or waxy?
If you want epoxy respect you, you must treated it correcty. Although modern epoxy are far docile than 30 years ago, when i started work with, still need a warm and dry place to harden and an accurate thorougly mix. If you can’t work like this go with polyurethane foam and polyester resin easier build.
So it’s feeling sticky I’m getting a space heater today to try and heat the room.
Also make sure to not mixed-up the weight ratio and the volume ratio. Don’t ask how I found out !
Yes let it fully cure in warm place and you will see. Must not be sticky when you sand.
Spackles that are rubbery and “ball up” when sanded are high Acrylic content. You have to be careful what you buy. Everybody used to use “Fast-n-Final” until the manufacturer decided to fortify their product with Acrylic. When you purchase read the label or open the container and take a look at the material. If it is grayish looking as opposed to white; It probably contains Acrylic. Acrylic spackle will give the finished blank a gray look and will ball up when sanding. Which means; small pieces will break loose when sanding and create scratches in the blank. What you want is a “lightweight spackle” that is white. Thinned with distilled water. Spread with a plastic spreader and fingers.
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Okay so I’ve spent the last couple of days trying different ways to heat up the area I’m working in and I can’t get it. Can I use rubbing alcohol to get the resin q cell mix off or put it in the sun or just wait for a hot day
If it stay tacky and rubbery instead of dry and crispy after many days in temp over 18°C that’s because your mix was of, too much hardener. You can’t dissolve it anymore before blank. Only way to go: lam over, take care to your mix (accurate by weight thourougly mix) work in at least 18°C dry place and let fully cured.
The big mistake i do: i invert resin and hardener for a seal coat, it stay a sticky rubber. I laminate over with one layer fiber more than what i expect, it work right.