I am using Golden Soft Gel Gloss Acrylic medium to bond a double primed linen to an ACM panel and having many occurances of air bubbles and non adhesion appearing 48 hours after application. The ACM panel was lightly sanded and coated with one application of the medium then let fully dry. A second coat of the medium was applied throroughly right up to all edges as well as one coat applied to the back side of the primed linen immediately before pressing the two surfaces together. Heavy weight was applied and distributed evenly over the 48 x 40″ panel as the two surfaces were placed in contact and it was set to dry for 24 hours in a 55-65º room with less than 50% humidity. After 24 hours the edges of the linen were trimmed to the ACM panel but serious edge puckering in the linen had occured and all four edges showed no adhesion for about an inch in. After 48 hours a dozen places in the middle of the surface showed air bubbles where none had appeared in the first day. I have lost faith in this medium as an adhesive for use with linen on this surface. Where this medium had worked adequately on small ACM panels before (12 x 16″ or smaller), this attempt was a disaster. Why am I seeing air bubbles appear so many hours later?
Your comments are very helpful, thank you.
Soft Gel should bond to scuffed and alcohol cleaned ACM. But keep in mind, that your surface is rather large and if the linen and gel is being sandwiched between two panels, then the water from the product only has the edge to evaporate through to dry and create a strong bond. This could take several days even in ideal drying conditions. Your smaller surface may have been able to dry much faster. Also, is the linen oil primed? If it has a hide glue sizing, then that can disrupt adhesion, as the hide glue is sensitive to ammonia in the gel and could soften and release if reactivated. At this point it may be worth trying a tacking iron to gently heat the acrylic gel through the surface to see if you can convince it to adhere onto the ACM.
Perhaps others will chime in with additional info on this last point of adhering with the tacking iron. You can always call GOLDEN if you want to discuss – 800-959-6543.
