Best Cement/Epoxy for working with resin bodies?

[Joe Lange]

Greetings All,

Looking for different opinions on what you all use for adhering resin together.  Especially when reworking a resin body.  I have used 'Mercury M300FM' cyanoacrylate adhesive, 'Mercury' 30 minute, (2 part), epoxy and also J.B. Weld, (original slow cure), with varying degrees of success.  I just acquired a resin trans kit body with a 'chopped/lowered' roofline that I plan to bring back to 'stock' height.  Needless to say, there will be a little bit of work involved.  What are your 'Go To' products for this type of work?        

[Oldcarfan27]

Super glue. 

Works fast and is permanent. 

Make sure you have everything lined up perfectly before you put a drop on it.

[Ace-Garageguy]

You're not going to like my answer.

I use MGS 285 epoxy resin and 285 (fast) hardener. It's over $300 per gallon, takes 24 hours for a full room-temperature cure, and likes a subsequent elevated temp post-cure to achieve maximum strength.

I use it because I usually have it in stock for real aircraft work, and when it goes past the use-by date, it's a write off.

It is used to build and repair high performance aircraft like the Cirrus SR22, and keep's 'em stuck together at 7g, so no worries about cracking while you're doing bodywork on a model.

For high-strength fill work over questionable substrates, I use West System 105 resin with 205 hardener, thickened with microballoon. 

It takes 12 hours for a room temperature cure, but the beauty of the stuff is that it takes very fine scribed lines beautifully, with no flaking edges...very important for scribing new door opening lines, etc.

 

[kruleworld]

5-minute 2-part epoxy or superglue work fine

[Joe Lange]

Thank you, fellows, for the input.  One thing I have learned after researching on the internet is that there is a definite difference between 2-part epoxy's.  The 'quick set' epoxys are not the best.  In fact, the 5 or 10 minute types are the poorest when it comes to strength and adhering.  Something to do with the chemicals they add to speed up the curing process.  The slower curing 2-part epoxies are supposed to cure harder and produce a stronger bond.  I started using Mercury's 30 Minute epoxy and noticed it immediately.      

[Bugatti Fan]

The quick setting epoxies are indeed as Joe said not as strong as the longer setting varieties. But for sticking static model parts together they should be strong enough in the main from.my own experience. The slower setting types come into their own, not only for the strength of the bond, but for more time to align and support parts properly before it starts to set.

Cyanoacrylates ( or Super Glues ) are good for many applications, but I have found that their shear strength is not very good in some instances.

Away from resin, for polystyrene, there are many tube, gel and liquid cements best for that material. I tend to use EMA's Plastic Weld Brand Liquid Cement as it is formulated to use on different plastics as well as polystyrene.

Edited October 23, 2022 by Bugatti Fan

[Mark]

The five-minute stuff tends to crystallize over time, at least it did for me.  I quit using the stuff.  A good super glue should do the job.  I don't use "gap filling" version, just the regular Loctite product.

I'd pay careful attention to minimizing, and making uniform, gaps between adjoining parts (especially where different materials are being joined).  After the parts are joined, I rout out the seam slightly on the back side and fill in with epoxy putty.  I suppose the back side could be reinforced with something like fiberglass cloth and epoxy also, but I haven't done that except on a couple of cracked hard plastic interior parts for 1:1 cars.

After routing and filling the back side, I do the front also.  On the finished join or repair, nowhere is there a visible join between two parts.  The surface transitions into putty between the two parts being joined.

[MeatMan]

I use CA on 90% of my resin build adhesive needs, but like Noel stated, it doesn't have the shear strength necessary in some applications.

In those cases I use two part epoxy and that combination has never failed me, and I'm kinda clumsy. ?

[Big John]

One word of caution, ok, more than one word, the CA clue can fog aluminum and some clear parts depending on composition of the material.

Edited October 22, 2022 by Big John
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