Epoxy or Resin as glue?


#1

Having grown up on the beach but being landlocked made me really want to recreate a little piece of the ocean. I’ve always loved looking through blue water. Well for anyone who saw my previous post I will say that smooth on “so strong” mixes swimmingly into the clear resin. I did premix a small cup so it blended more evenly in larger tank. Form2 had no idea the resin was tinted and this does not seem to have any effect on final strength or polish.
Here’s where I’m fuzzy and want some advice…
Epoxy or more clear resin to seamlessly glue the 2 together with…little bubbles? (I want to control where these bubbles go eventually)
Sanding is important and clarity. As of now I have plain old guerilla clear epoxy and think it’s actually the best way. I’m worried that adverse effects occur when I try to use my blue handheld laser or sunlight to cure through the clear to glue these together. Another important factor will be the paint I use over white to look like reef. I still need a bond to occur and am not sure if painting it will negate any and all bond between these?

The base is white resin too btw and yes they keyed together on the first try!
https://drive.google.com/file/d/1IqP0_GWi8amBzxA949_5ViCCJThOkhUM/view?usp=drivesdk

https://drive.google.com/file/d/1LzTGc9VQPZUX7TZgcfsU8jzwHi53xzjP/view?usp=drivesdk

https://drive.google.com/file/d/1R6Y41Wlj-k1LAuCW3AEXWXjpr9_2TKMU/view?usp=drivesdk


#2

It really depends on how strong a bond you want.

I’ve used resin to join parts together, and a blue laser to cure it. It works pretty well, but it doesn’t hold. If you apply some reasonable force, the parts will come apart. So if your model is just for looks and will not be handled too much, resin does a reasonable job

Epoxy on the other hand, will create a long lasting bond. You can get hobby grade 2 part epoxy in a variety of setting speeds. I like to use 12 minute epoxy as it gives itself time to flow nicely into all the crevices and create a nearly perfect blended-in look. It also cures totally clear. Gorilla epoxy and other epoxies fro the hardware store tend to yellow as they cure, which is not a real problem if you plan on painting the model.


#3

I agree. No matter what you do resin never gets cured very deep into the joint.
Resin is very good at filling holes.


#4

I did a bit of tensile testing here with various adhesives. These were n = 1 and I’m going to run a few more trials and expand this, but resin welding did fair best in terms of tensile strength.

Process might be important here, and I tend to cure the resin on the joint with a UV laser, and then put the entire part in Form Cure to ensure that it cures all the way through. This also has the advantage of a seamless surface finish and consistent material properties after being post-processed.


Flexible resin resistent to fuel?
#5

Yikes! So resin works but I’ve been successful only when curing without the upper blue piece to shine through. That or leaving in sun or under a handheld UV wand are my current options. I have intense sunlight here so I’m gonna try that with a couple pieces clamped. It seems a thick cured layer inhibits the curing. I should try non tinted clear possibly too?
The yellowing of “clear” epoxy seems minimal and the idea is to see the reef colors through the clear! I do have some concerns that unless I leave an area without paint that will just leave a weak bond…so maybe a perimeter of white which unfortunately shows through…or! Even fasteners of some type has crossed my mind but it’ll break the flow of this idea.
Full color printing makes sense for the base so there’s no paint layer but I’m working with what I have here and now. That’ll possible be next though ink bleeding could occur and the porous nature of full color prints would create more bubbles I’m guessing too.
Hmmm…I really think a longer curing epoxy after a degas in a vacuum might be best but the 2 epoxies I’ve been using don’t seem to like giving up all their bubbles in ours. If a resin test works itd be ideal simply because I could hand sculpt and add elements in afterwards seamlessly…and it does produce the least bubbles.


#6

That is just lovely!


#7

If you do go the resin welding route, you’ll want to make sure to use a curing unit to ensure that the part is cured all the way through. Heat and light work together to initiate curing, and the introduction of heat with a curebox helps to ensure that the bond is solid all the way through.

Shining a laser through Clear Resin somewhat deceptively might not work. There are photoblockers in the resin that prevent light from penetrating beyond a couple hundred microns even though the material may appear clear.


#8

Oh man looks sweet!


#9

Really nice piece!


#10

for a far better result… forget printing the reef as a separate part, Just print the wave in clear with the reef underneath as a negative relief…
Once the print is out… you can simply PAINT the negative space underneath and it will appear as a positive with perfect clarity thru the resin from above.

This is how we used to do, for example, museum displays that show a CLEAR shark with its internal organs visible… the organs are not solids inside the clear shark exterior- they are simply voids cast as the inside surface of the clear shark shape, and then painted from inside… details like veins molded into the surface as a negative space look solid and suspended from the outside of the positive space.

If you want the result to have a solid feel- you can first paint the negative reef detail, and then BACKFILL the negative space over the paint with any resin that will cure solid.


#12

Thanks I’ve considered that and whilst easier I think a small part of me wanted to see if these would key or align up! I will say casting resin can have it’s own set of issues I avoided. I know mushroom effects won’t happen that way but rather as a mold process mixed in. I want to add air bubbles in the next one! That’s gonna get trickier…some can be channels as waves have.
All this with full color SLA becomes a 1 file setup too so that’s also gonna make this even better. I want a surfer in there too you know it!


#13

they almost certainly won’t. printed parts simply don’t have perfect dimensional output. And if you are gonna paint the surface of the ‘reef’ then your matching print must be offset by the exact thickness of the paint you apply.- whereas a resin backfill will match molecule for molecule.

The thing is that the result is not only easier- but far superior in its result.

You can use Water Clear urethanes- that are far less obnoxious than polyester… and have much lower shrinkage.


#14

Hey, your information are quiet useful. Thanks for it. Now i want to add my knowledge on epoxy resins.
Epoxy resin gives glossy and high shine finish that we have all come to associate with river tables. Although you can use stains and other types of paint jobs, most of these are not long term options because they tend to get damaged and required touch-ups on a regular basis.
However, to get the best results, you need to be very careful choosing your epoxy resin, because there are a lot of products in the market that do massive damage to your beloved projects. One of its comprehensive guide is mentioned below:-


The things which we can consider before getting a good epoxy resins Like
Buy only brand name products
Find a company that has a long standing experience with making epoxy

Hope it helps