Floral Block Topcoating
Updated: 3 days ago
Top-coating may not always be necessary, but some people need to or prefer to top-coat their floral block pieces regardless.
If using a thicker viscosity resin, you can preheat the bottles in hot water. Water will warm them up fastest. Then using an infrared thermometer, aim it down the neck of the bottle (with lid off). You want it to reach a temperature of about 78-80F before you mix the two parts (A & B) together. Once you mix them together, you will need to pour it onto your surface as quickly as possible. So always have everything ready prior to mixing.
Note: If resin sits for long in the mix cup at that temperature, it will get hotter and hotter and prematurely exotherm in your cup, and the cup will need to be taken outside, then thrown out after it cools.
If not using a thicker viscosity resin, you may not need to preheat the bottles. Check if they are about 74-78F range prior to mixing the two parts (A & B) together. It is a bit lower in viscosity so does not need to be heated as high.
Once you have applied the mixed epoxy to your piece and spread it out, give it a light torching to remove surface bubbles. After light torching wait about 5 minutes for below surface bubbles to rise, and then give it another light torching. Repeat waiting 5 minutes and light torching a few more times. About 3 - 5 light torches total should do the trick.
Keep in mind pre-heating any epoxy reduces available work time, but for clear blocks/pieces, it is important to do this to assist with reduction of potential micro-bubbles that will really show on any clear pieces. Also remember, once you've mixed warmed up epoxy, it needs to be poured on to the substrate as quickly as possible. Never leave it to sit in mix cups.
You can trim edges using a deburring tool, then tape up the sides of the block (to prevent unwanted drips on the sides), right up to the top edge. Be sure there is no tape above the edge or epoxy will dry with a lip that will need to be cut off. You want it to softly flow over edge.
I also placed the tape to hang past the bottom, so no resin drips go on to the bottom flat edge. Some find it safer to tape off the whole bottom as well. I set the piece up on sturdy cups for support and to allow any drips to hang from the tape. Use a level to ensure your piece is level.
Instead of tape, some people brush Elmer's Glue All adhesive (or Liquid Latex) on to the sides and bottom, and let that dry, instead of using tape. Two thin coats is apparently better than one thick coat. Allow to dry fully before setting on cups and pouring resin. The drips peel off when you peel of the Elmers Glue All/Liquid Latex.
There are people with severe allergies to latex, so best to check with customer if planning to use the Latex.
After the sides and bottom are protected from potential drips, pour the flood coat. Pour it in the middle (of the top of piece), then carefully nudged it out & up to the edges, trying to keep it all on the top, to give piece a bit of a domed like finish with a slightly smoother rounded edge on that front side.
Demould the piece first, before topcoating is a good idea to get the nice smooth edge, plus top-coating resins will have bubbles, and you do not want to torch a piece while in the mould. Torching or any added heat can ruin your moulds, or can even cause your piece to fuse to the mould. Once your piece is out of the mould, you can safely proceed with torching resin, to rid bubbles.