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best glue to attach small objects to semi-gloss enamel surface

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31K views 9 replies 6 participants last post by  LMHmedchem  
#1 ·
Hello,

This isn't exactly a wood finishing question, but it involves the finish so I thought I would post it here. Feel free to move this if there is a better place.

At any rate, I need to glue some small applique decorations to an oil-based enamel semi-gloss surface and I am wondering what glue to use. These are small wooden and cardboard figures that have been painted and clear coated with gloss acrylic. One issue is that because of the irregular shapes, I don't see how I can sand the gloss off of the surface before application. I would like a glue that will adhere very well and it would also be nice if it didn't take overnight to reach full strength though that isn't a deal breaker.

A few of the figures are a bit warped. They are reasonably flexible and will press flat, but it would help if the glue was strong enough to hold these warped pieces flat after it has set up (I will clamp until it does).

Of course it would be a problem if the glue caused the paint to lift. The last coats of paint on this are spray oil-based enamel. How long should I let that dry before I try to glue to it?

Thanks again for the advice,

LMHmedchem
 
#5 · (Edited)
Use a CA glue with activator, medium is PLENTY strong
I am often afraid of CA glue because of the very short set time. These really don't leave much margin for error. I'm not sure what I would do with the activator in this case since I have small objects of irregular shape and a surface that is already finished so has to remain clean other than the spots where the objects are attached. I suppose I could spray the activator on the back of the objects and put the glue on the painted surface, but again, there is no margin of error here and no chance to make adjustments and clean up excess glue. If I use a super glue, it would probably be a single component with a >30 second set time. That would be long enough to position the object, adjust it if necessary, and wipe up excess before it sets.

On woodworking for mere morals he talks about a glue I think its call weld bond. This glue is suppose to glue painted surfaces together without clamping them.
I think I can get this at Michael's, so I will check that out. I might also mention that I am short on time, so I really can't order anything. That would leave me something I could get at Home Depot, Lowes, Walmart, Ace, Michael's, etc.

Are you sure you want "glue'...and not just a few dots of Caulking/Silicone to hold them in pace? Even "regular" latex caulk is a pretty good bonding material.
Something like that might work. There are two issues here. I have several small wooden stars to attach, some of which are a bit warped. They are about 3/16" in thickness, so they are flexible. There are allot of things that will secure these, but I am worried about the warped sections pulling up the paint that the glue is secured to, especially since the paint is just a few days old an not cured. Because of the flexibility of the caluk, I would expect it to have difficulty holding down the warped edges. I have looked at construction adhesive like liquid nails and the Gorilla brand.

I am considering tracing out the stars with a fine pencil and using a dremel with a sanding disk to take the paint back down to wood where the stars will attach. Since the stars are wood and the backs are unpainted, I could use a good wood glue to attach them and have no fear of them pulling up at the warped edges. The rest of the figures are 3/16" cardboard that has been painted and finished with 6 coats of gloss acrylic. These would probably stick on with a bit of chewing gum and stay just fine. For the cardboard figures, I am only worried about the glue solvent delaminating the enamel paint on the surface or damaging the cardboard.

LMHmedchem
 
#7 ·
Well I glued my stars on in the way I was thinking. I traced the outline with a pencil and then used a dremel to remove the paint inside of the pencil outline. The sanding disk was too hard to control so I used a small pointed grinder. I left about 1/16" of paint inside the trace line. I a small paint brush to fill the unpainted surface inside the trace line with wood glue. Then I painted the back of the star with glue. I pressed the star down, wiped off excess glue, and clamped down the star with a board and a clamp and left it overnight.

This method was reasonably successful. I definable needed to clamp down the star to get the curled edges to lay flat and stay that way after the glue had dried. I think there is a good bond now between the wood on the back of the star and the unpainted wood on the surface. There was some glue that leaked out and I had to remove afterwords. I also will have to touch up some around the stars. I glued one set of stars using a board that must have had something on it. Two of the start picked up some junk on the surface which was a problem. I had to re-sand them to get the junk off. This, of course, meant that I had to re-coat them with clear acrylic so I had to tape off the stars so I could re-spray. This is more touch up that I was hoping for but I think it will turn out fine with a little more work. Most of the stars were clamped down using old pieces of 3/4" azek and those turned out fine. It would seem that azek is a better choice as a glue support.

I will try the cardboard figures later today and see how that goes. I think I will be using weldbond, but I'm still not quite sure.

LMHmedchem
 
#10 ·
If it's important I would make a shallow cut with a straight cut router bit enough to remove the paint and use wood glue.
This is essentially what I did for the stars, which were a bit warped and needed something to hold them flat. I used a dremel instead of a router since the most warped part of the stars was near the tips of the rays and I needed a small tool to clean that area out. On the whole, this worked well.

I used weldbond for the other figures since they are light and very flat. Since one surface was non-porous (painted) and the other porous, I used the instructions that said to paint a thin film on both surfaces, allow to dry for 1-3 minutes and then press the 2 surfaces together with a twisting motion. I could feel the surfaces attach immediately, though they could be re-positioned for a little while as well. I don't know exactly how long, but 15 or so seconds anyway, probably longer. Since these are odd shapes, I painted a small area of weldbond on the painted surface near the middle of where the shape was supposed to go. This was not nearly as large as the entire shape, but the entire back of the shape was painted with the weldbond. A day later and everything looks great. I will post back later if for some reason the adhesive doesn't hold up.

I had to touch up some around the stars and so I used a small brush and some of the brush on oil-based semi-gloss enamel to do that. For some reason, these areas look flat in appearance and not semi-gloss. I sanded the areas with 400 before doing the touch up. The rest of the surface was finished with spray on oil-based semi-gloss enamel of the same brand and then polished up with 0000 steel wool to remove a little roughness from dust and such. I guess I can try using the steel wool on the areas that look flat and see if they will shine up.

Any advice on what to do about that? I have two coats of touch up on there, so I don't think that adding more paint will help.

LMHmedchem