ive made a couple of boards now, but with this one not all went so well with the shaping so i thought id use it to practice some graphics, tinting etc on it.
Its not been too bad until i came to try a gloss coat. I`ve made a pinline using masking tape and acrylic paint. This was left to dry and then i lightly sanded it.
However, when i came to apply the gloss coat using resin research epoxy, it was looking good after id just applied the coat, but a few hours later when itd dried, its like all the resin ran away from the pinline in some areas.
I`m guessing some contamination possibly, but i did lightly sand the pinline then wiped the whole board down with alcohol before glossing.
Is it possible to use acrylic paint under resin research epoxy? I used used some posca pens for writing elsewhere and this turned out fine. There is also a large dot (about coin size) where the same reaction looks to have taken place.
Aswell as this, i also seem to have another reaction which looks like a sort of dried water mark in the resin - ive taken pics below of this aswell. I tried wet sanding with 400 grit but it doesnt appear to want to come out!
Any help is appreciated - im learning here! Something else to note (which i can see some people shaking theis heads already!!) - i didnt have any pigment for the resin, so i went to the kitchen cupboard and mixed in the spice turmeric which turns a nice shade of red when it hits the resin. Not had any probs so far with it until no though.
Deadshaper says some yellows are more problematic than others. Something about Hanza yellow??? I don’t remember… He was talking about poly resin, but maybe there’s a similar risk with some yellow pigments and epoxy as well.
Next time put the pine under the hotcoat? next time maybe don't pigment the gloss coat...whats up with that. Golsses are supposed to be clear....always clear.
If you are doing color work either do it in the lay up, or do it on the foam. Never in the hotcoat, or gloss.
1) I think you used too much paint, or 2) you cut it with something wierd like future floor polish? I always do my epoxy pins under the hotcoat, or I do them in india ink, or I do them with automotive pinline tape...Or I do them with those little rolls of 1/8 masking tape. The masking tape stuff works good.
I just did my first acrylic pinlines using Liquitex paint and it went flawlessly using the same basic procedure as the original poster so my guess is its the paint he used.
cheers - i think i probably used too much paint, as when i put it on, it was quite thick. Think ill probably sand it down a bit more then try glossing over that area again to see if i get the same result. If it reacts again, i have some yellow pigment which i can use for the pinline so its made from resin and shouldn`t’ react(!)
Id be interested to know about pinlining onto the lam job - i just thought it would be easier to do this on top of the hotcoat as youll be applying the paint to a smooth surface as opposed to lam layer which is quite rough and you would struggle to get sharp lines? Please correct me if i`m wrong!
You’re right. I’ve always done them on the hotcoat if I’m doing a gloss coat, or on a basted area over the lap line if I’m only doing a hotcoat. I’ve also done them over a basted lapline on around an inlay panel, then done a clear second lam over it. then hotcoat/gloss. THAT works great, and you’ll never hit the pin.
I’ve done tinted hotcoats, but only if I’m after a specific effect. It’s not SOP.
Yup. this may be the first time I’ve ever heard of someone doing color in a gloss coat.
By the time you get to the gloss, all color work should be over with. Given the formulation of most glossing resins, I’d assume they don’t play well with pigment.
Yeah, i know - doh! Lesson learnt there i guess!! Won`t be doing that again - not sure what went through my head when i decided to do that - quite amusing though!
Ill sand it back where ive had the bad reaction tonight and redo the gloss coat it with no tint - see if it reacts again.
The gloss coat did go hard though. I used resin research epoxy for the hot coat and also for the gloss coat - is this right? Ive been reading that maybe i shouldve added some additive f to make it easier to sand?
Looking forward to making the next board and not making the same mistakes.
I think that acrylic you used had some oils in it, even though it says "thin with water"
Ive had water based acrylic that had some oil in it and it messed with a few gloss coats but not as bad as that.
I have also used a water based spray paint that didnt like to be coated at all.I think when you did the alcohol wipe you spred the contamanant across the board.
I had a eureka moment last and think i know maybe what caused the reaction.
I reglossed the board last night after sanding the pinline and bad areas all away - great fun(!). no turmeric this time.
I checked it a few hours laer to see how it was getting on - all good apart from 4/5 small finger pad size areas where it had reacted similiar - no real issue for me as im practicing really. Realised that this time i had forgot to wear gloves when handling the board after sanding and i didnt wipe with alcohol either.
This got me thinking about how i applied the original pinline. When i did i, i squeezed a thick line of paint round the board edge where it was masked for the pinling. I then (without gloves!), ran my finger all the way round, flattening it flush with the top to make a nice solid colour. I then lightly sanded the pinline before glossing.
I reckon i contaminated the pinline with oil from my finger when doing this!
I just had a brainstorm. When you say you rubbed it down with alcahol what did you use? Did you use household alcahol from the drug store? My understanding is that some of the drug store alcahols actually have moisturizers in the mix. What did you use for a rag? Again another possible source of contamination. Epoxy is extremely sensitive to any sort of oils. The other problem with wipe downs is if you are not using a two rag system you are likely just smearing any contamination around and not really removing it from the surface. My procedure has been to take the board up to the shower where I wash it with warm water and a special super secret chemical. (Dawn Dishwashing Liquid)
