Hello with a coming back sun !
I hope that everyone’s fine and survives the end of the “school” year (exams, overbooked agenda, etc).
Here a new article to tell you about our first backpanel’s reproductions + the small cast of the bottom of the piece.
Some photos, our results, observations, attempts and solutions ; I wish you a nice reading. =)
Everything began little more than a month ago, as the rain and cold of May in full swing were. While all the holy people were drowning between blankets, slippers and hot drinks, we were trying in Choulex to put up a tent in the garden, and under a snaky wind who harasses tarpaulin and twines, were moving all the equipment from Quentin’s room to this makeshift shelter.
We don’t work in vain ! After organized, doodled, spammed during several weeks, a first team of motivated peoples came a weekend for THE first molding. Big thanks to Yannick, Paola, Florian and Florian’s friend for bringing camera. For the second cast, we’ve got Loïc, JC, Yoan and Yannick. Thanks to them again !
You can turn off the music
I point out that being five people is really the bare minimum to be effective, chain quickly so the layers don’t have time to dry completely (because they dry quickly!). They must always be partially sticky / wet to adhere to each other. As for being more than 5, it is really luxury, you can then raise the head of toxic fumes and stretch in order not to break back and neck to be bent double non-stop.
After cleaning the silicone mold and prepared the material, Quentin has briefed us. He also warns that once launched, it would be non-stop for at least 2 hours.
First mixture: gelcoat and black coloring (basic color of a segment). It is spread with medium brushes in order to put the gel in each gap. After waiting about 15 minutes for the gel to stick but not remain on fingers, we continue with resin and fiberglass. It is important to:
- Not using to much black colouring agent. The piece will be too dark
- Mix well the gel to the colouring agent in order to avoid a first layer with some spots more lighter than the rest.
- Be particularly careful to the bubbles that the gel can create, et be sure all the reliefs and the chinks are full.
Please Note : Using a toothpick on the 2nd backpanel has been positive to minimize the bubbles.
We cut the fiberglass first, then mix in other bowls the resin and the thixo, we stir well and let’s started for a tapping with brushes soaked with this mixture. It must tap (and not spread) on the tissue to “wet” it and stick it to the gel coat. The product’s mixture transforms the fiber in some kind of filamentous jelly. Rubbing is precisely what creates the most wrinkles and bubbles.
We starded from the left side of the piece and proceed step by step until the end. Being methodical is a good way to not forgot area and starting again with a second layer once at the other side, because the beginning of the piece is dry.
Warning: this means that there are two glass mat layers to cut ! It’s really recommanded to have the whole pre-cut glass mat in order to avoid a “Oh shit, I forgot to cut enough,” the brush thrown anywhere (in the gravel for example ) and a rushe into the house with scissors (my own experience…hum).
The fiberglass, cut either in average bands or in small ones (it’s better with small ones) doesn’t lay well on the piece’s reliefs. We experimented that giving cutter strokes around the bumps reduces a lot the amount of bubbles. Please note that the cutter/scissors used for this will be unusable at the end. However, if you soak it in white spirit immediately after completing, its life could possibly stretch to the next cast. This is one of the advantages of being many, a person can only focus on the aim “scissor kick”, while others play with bowls and brushes.
Once the two layers made, we let dry (at least one hour before unmolding).
We noticed that the first backpanel slightly twisted when it finished to dry out of the silicone, we decided to leeavefor a week. It was pretty conclusive. However, the release was difficult. Because the piece was totally rigid, it was necessary to be very careful not to tear the silicone.
First and second backpanel out of the silicone placenta.
By far, they are beautiful, they are great, we love them ! Closely … Quentin grumbles (Well, we know, he’s a perfectionist, chuut). Here is why he’s a bit disappointed :
1) Some kinds of spots. They must came from the silicon mold itself, but with paint, they will probably disappear.
2) Breaks in the angles, most notably on the small squares. Unfortunately, that can’t be fixed. Before the silicone molding, I made the unbearable work of precision to fill them all with plastiline (made at the exact continuity of the shape, if that it’s not love of well done work) but nothing hold (sniff).
3) Some kinds of black masses. They’re bubbles inside the silicone itself and we didn’t see them during the molding. Gladly, those masses can be easily remove with a milling machine.
About the bottom of the piece – some of you already saw pictures on facebook or in the previous article- it has been done by Quentin and myself the weekend before the second backpanel. We wanted to test different things like : working with smaller fiberglass’s bands, how to do better to improve ourselves not making bubbles, etc.
The result was nice, even if there were big internal bubbles. For now we use that piece like a training piece. Indeed, it completely twisted in a week, because we had cut the edges, it was very light and not totally dry. We already tested some shadows with paint, filed the edges with the milling machine, et soon we should fill the holes with resin + mastic.
Well that’s that, it was really a big work that we have only to make…7 times again ! (argg)
We have to order materiel (and 2000 bucks more !). But this time, instead using glass mat, we will use fiberglass for the first layer (after the gel coat). That’ll allow to be more precise. Because using scissors is fun, but gives not a perfect result.
Otherwise, we let us the choice if we making a third layer of resin (=additional costs) because of the lightness of both previous backpanels. They become too flexible.
As always, we let you know 😉
Have a good week end !