Gluing delima

[m408]

First of all, forget my "advanced" status. It is based on my number of posts on this forum, most of which are questions such as this, and not on my building ability, which is just a tad beyond novice. I know that you builders who are actually "advanced" have run into this problem sometime in the past.

I get a frame, body, or engine painted and then find that I have to add a part, shocks, bumper braces, etc. What do I do to attach them other than trying to scrape a tiny area, which I can almost never get to with a hobby knife. Is there a glue, ca, or epoxy that I can use on painted parts?

I have tried what I call "dry builds" where I do as much assembly as possible using double sided masking tape as an adhesive to locate and mask points that will require future parts before any painting, but always miss some.

Edited August 13, 2007 by m408

[ismaelg]

Hello,

That will depend among other things on how strong you need the bond to be. Each option has its ups and downs. Plastic to plastic, as you mentioned the best way is to scrape off the surface with a hobby knife and use plastic cement. It doesn't have to be a large area, just enough to create a bond. If that is not possible, you can use superglue. The advantage is that is in fast and strong, disadvantages are that it can fog the paint (bonding area looks white) and since it is fast, you will have little to no time for correcting the part positioning. Avoid using superglue straight from the tube, as it can be messy. I take a piece of thin wire, do the smallest loop in one end (or just bend it like a small U shape) and use it as an applicator. This will help you use just the smallest amount.

Five minute epoxy is very useful as well. It bonds plastics and other materials and will give you some time for position adjustment. I personally prefer the clear one. But it requires proper mixing and you only have a few minutes to use it.

But not every joint needs to be structurally strong. Sometimes you want to attach something small that doesn't require a lot of strenght. For those things, I use good old white glue! Yes, the same glue we used in school. I also use it for attaching clear parts as it dries clear. White glue is very safe but it is also very slow. By the way, never never, never, EVER use superglue to attach clear parts.

Regardless of what glue you use, scraping the areas is always a good idea, provided it is feasable and safe.

I hope this helps!

Thanks,

[LT]

I usually always use CA glue unless the job calls for epoxy.

It sounds like your concern is more about damaging paint on parts you've already painted. 99% of the time some touch-up painting is required to cover glue bonds between two parts so scraping painted parts, if necessary, before joining them isn't a concern if done carefully. Once joined, touch it up with a fine sable hair brush and try to blend the brushed finish with the already painted finish.

[Steve H.]

Ismael is right on with his glue hints. The only things I can add are...

Clear acrylics work well, but have poor structural strength.

CA or epoxy will always be stronger than the paint. If the joint does come apart, it will take the paint with it.

I scrape paint off of very small areas with the tip of my exacto knife. When I can't clean the area, I go with 5 min epoxy, most times.

[m408]

I usually always use CA glue unless the job calls for epoxy.

It sounds like your concern is more about damaging paint on parts you've already painted. 99% of the time some touch-up painting is required to cover glue bonds between two parts so scraping painted parts, if necessary, before joining them isn't a concern if done carefully. Once joined, touch it up with a fine sable hair brush and try to blend the brushed finish with the already painted finish.

Not so much concerned about paint damage, (my paint jobs are not that great, rattle cans in the garage etc), but strength. Main problem areas are places hard to reach with a hobby knife that have been painted.