As many of you know, I am looking at various alternatives to build a series of freight houses for my layout on which I have a large downtown passenger station. At the site of the actual prototype, Dearborn Station in Chicago, there were a series of long 1-story and 2-story freight houses.
In my search, I have concluded that the Walthers Modulars best suit my needs. The problem is that the modular kits have been long discontinued and have become harder and harder to find. I am still purchasing kits when I find them, but that is no longer to easy to do. So, I have resorted to making rubber molds and resin castings.
The resin castings are very good reproductions of the originals, but the problem is finding an effective adhesive. Plastic glues simply do not work. Those who have cast parts in resin suggest either CA glue or 2-part clear epoxy glue, but I have had no luck holding the modular wall sections together with either of these alternatives. I have tried fast curing 2-part epoxy (not an actual glue but an epoxy plastic), but that only results in a mess.
The bottom line is that I have not yet found an effective adhesive. The closest thing that I have come across is the resin mix itself. I thought that was the solution and maybe it would be on a completed structure, not to be handled again. But, it is not that difficult to apply pressure and break the resin bond. So, my search continues for an effective adhesive.
I would welcome any suggestions from anyone who has actually produced a strong bond when connecting resin parts together.
Rich
Alton Junction
Rich,
It would help to know, what the chemical properties are of the resin You are using...there is more than one type. I have never heard of anyone having any difficuties with using resin to resin for adhesive......especially in the Automotive industry. I'm not doubting Your word....I just find it hard to believe. If everyting was done correctly, mixing etc. It should have produced an unbreakable bond. I believe You may be looking for an instant bond which will be hard to do and still produce tensile strength. I'm going to stick My neck out and suggest an adhesive that I have used before and is highly recommended. Made by Weld-On....follow the directions precisly and it should produce a seamless bond in 24hour cure time that is 1700 llbs strong...it starts to set in 5-minutes, in ten minutes it starts to weld together...mix in with the materials for a seamless bond. Use in well ventilated environment.......fumes can be toxic if continously exposed to it.
https://www.amazon.com/SCIGRIP-Acrylic-Cement-Low-VOC-Medium/dp/B005ZH31W2/ref=pd_sbs_328_2?_encoding=UTF8&psc=1&refRID=H5W53J3REM6HVRYFG9YJ
Good Luck!
Frank
Hmmm, CA has always worked for me. A couple of suggestions...
What are you using for a mold release? I assume you're cleaning this off, but maybe need to check that it's actually getting it off the finished casting.
What does the resin manufactturer recommend for an adhesive? Castings are rarey used entirely on their own, so that usually means the resin is intended to be glued to itself and other materials.
Mike Lehman
Urbana, IL
Slightly OT. Another source for Walthers Modulars is already built structures sold at train shows and ebay. I once purchased a structure at a train show built from DPM modulars. It was so poorly built, it was falling apart. I successfully disassembled the structue and ended up with nearly 25 wall sections for less than 10 bucks.
Since many folks use CA to assemble structures, they can be snapped apart or aided by a hobby knife slicing into the joints. A little sanding on the joined side and they are as good as new.
Not disuading you from using resin, but there's no reason to not browse train shows or ebay since they may yield some modular structures that just need some disassembling.
- Douglas
I have built plenty of resin kits from Westerfield, F&C, and Sunshine. I use Loctite Super Glue Gel Control in the "blue wing" bottle for all structural hidden joints. I re-enforce these joints with pieces of 0.100" styrene.
.
I have always had excellent results.
-Kevin
Living the dream.
As mentioned above, I have had no problems using CA for resin kits. An alternative may be 5 Minute Epoxy
Do you use some kind of mold release to keep the resin from sticking to the mold? First that needs to be cleaned off. I use Zep Heavy Duty Citrus Degreaser from Home Depot. I spray the parts, then follow with a warm water rinse
http://www.homedepot.com/p/ZEP-24-oz-Heavy-Duty-Citrus-Degreaser-ZUCIT24/203249483
A light sanding with very fine sandpaper on the parts that go together may also help give some tooth get the adhesive to stick.
George In Midcoast Maine, 'bout halfway up the Rockland branch
zstripe Rich, It would help to know, what the chemical properties are of the resin You are using...there is more than one type. I have never heard of anyone having any difficuties with using resin to resin for adhesive......especially in the Automotive industry. I'm not doubting Your word....I just find it hard to believe. If everyting was done correctly, mixing etc. It should have produced an unbreakable bond. I believe You may be looking for an instant bond which will be hard to do and still produce tensile strength. I'm going to stick My neck out and suggest an adhesive that I have used before and is highly recommended. Made by Weld-On....follow the directions precisly and it should produce a seamless bond in 24hour cure time that is 1700 llbs strong...it starts to set in 5-minutes, in ten minutes it starts to weld together...mix in with the materials for a seamless bond. Use in well ventilated environment.......fumes can be toxic if continously exposed to it. https://www.amazon.com/SCIGRIP-Acrylic-Cement-Low-VOC-Medium/dp/B005ZH31W2/ref=pd_sbs_328_2?_encoding=UTF8&psc=1&refRID=H5W53J3REM6HVRYFG9YJ Good Luck! Frank
I don't know if all resins have the same chemical properties, but I have seen at least one manufacturer of resin parts for hobbyists refer to resin as a polyurethane.
mlehman Rich, Hmmm, CA has always worked for me. A couple of suggestions... What are you using for a mold release? I assume you're cleaning this off, but maybe need to check that it's actually getting it off the finished casting. What does the resin manufactturer recommend for an adhesive? Castings are rarey used entirely on their own, so that usually means the resin is intended to be glued to itself and other materials.
After I started this thread, I found some suggestions for resin parts adhesives that said to use fresh, thin CA and only apply it to one side of the parts to be joined. On that suggestion, I plead guilty on all three points. I am using an older bottle of thick CA and I apply it to both sides of the joint. So, I will go out and buy some thin CA and apply it to one side of the joint.
The manufacturer recommends either 2-part clear epoxy glue or CA.
SeeYou190 I have built plenty of resin kits from Westerfield, F&C, and Sunshine. I use Loctite Super Glue Gel Control in the "blue wing" bottle for all structural hidden joints. I re-enforce these joints with pieces of 0.100" styrene. . I have always had excellent results. . -Kevin .
For building resin kits like those from Westerfield, Funaro & Camerlengo, or Speedwitch, ca works quite well. However, the components are relatively small and are eventually assembled into a box-like structure which improves its strength.I've assembled a Korber cast resin roundhouse, though, and found it didn't work well at all, nor did JB Weld epoxy. I finally resorted to using machine screws in conjunction with the JB Weld, and ended up with a very solid structure. It included a one-piece screwed-on floor, too, which greatly helped hold things together.
All corner joints were made with screws and epoxy, and all butt joints done using epoxy within Evergreen H columns...
However....
richhotrain....At the site of the actual prototype, Dearborn Station in Chicago, there were a series of long 1-story and 2-story freight houses....
...to assemble such a structure from individual wall sections, the gluing surfaces of the edges are much too small to provide sufficient strength to allow even simple handling during construction.
I'd suggest that if your planned structure is going to be anywhere near the scale length of the prototype, you should purchase a 4'x8' sheet of .060" styrene. This will allow you to use a utility knife and straightedge to cut full-length backing sheets for all modelled walls and also create plain walls for sides of the structure that will not be seen. There should also be enough material left to enable you to create interior partitions that will give the structure more strength (which will keep the visible walls straight) and probably enough left to also make a roof for the whole thing. The latter could simply be painted or used as a support for a more detailed application of roofing.
Here's a kitbash of Walthers kits to create a larger structure...
...note the plain styrene used for the normally unseen back wall and the interior partitions, which were added to impart stiffness to the structure...
doctorwayne richhotrain ....At the site of the actual prototype, Dearborn Station in Chicago, there were a series of long 1-story and 2-story freight houses.... ...to assemble such a structure from individual wall sections, the gluing surfaces of the edges are much too small to provide sufficient strength to allow even simple handling during construction.
richhotrain ....At the site of the actual prototype, Dearborn Station in Chicago, there were a series of long 1-story and 2-story freight houses....
When I tried the resin mix as an adhesive, it did work. But, because the final structure will be 40" long, I was concerned about long term stability. So, without totally forcing the bond to break, I applied some pressure to the two wall sections that were glued together with resin and easily broke the bond.
I need some time to study the suggested steps that you detailed in your reply. Thanks for taking the time to do that write-up.
mlehmanWhat does the resin manufactturer recommend for an adhesive? Castings are rarey used entirely on their own, so that usually means the resin is intended to be glued to itself and other materials.
Here is what it reads.
Bonding something to Alumilite works best when the material is still curing or shortly after demolding. The best adhesives for bonding Alumilite are ones that promote a chemical bond. Adhesives that work include but are not limited to: MMAS, epoxies, CAS (super glues), one part silicones, one part urethanes, and hot melts.
I'm not sure what all of those adhesives are, so I need to check that a bit more.
Fresh CA definately works better than old CA. And if you have not tried CA accelerator, get some. You will never be without it again.
When all else fails, "Gorilla Glue", or "Elmer's Nano Glue" (I think they are the same thing) will hold ANYTHING together.
However, both expand while curing, and the pieces must be clamped until fully cured. Also, any surface they touch will be ruined forever. I go to these as a last resort, but they sure do work.
I made a trip to Hobbytown USA today and picked up a fresh bottle of thin super glue to replace the old bottle of medium super glue that I was using, and I applied the super glue sparingly to only one side of the joint, per instructions from a hobby manufacturer's website.
The directions said that a firm bond would be achieved in two hours. So, I waited two hours and it looks like the bond is holding quite well. For added assurance, I then applied a thin coat of super glue to the joint on the inside portion of the wall sections. I waited two hours and checked once again. The glued joint seemed even stronger.
So, it looks like my search has come to a successful end. Thanks to all who offered suggestions and advice.
It's very true that new CA is better than old CA, and shelf life can be enhanced by keeping it in the refrigerator. If it sits on the shelf at the craft store for a long time, it can lose its effectiveness. My local hobby shop keeps CA refrigerated. Bracing can help, and an inperfect fit can be improved by using gap filling CA. I usually use Zap. All resins castings will have some residue of the mold release material used in the casting oprocess. This should be removed with a detergent, and it often helps to distress the surface with sandpaper or a file to give the bond some "tooth".
I rarely use accellerator because I have heard that it creates a weaker bond, and the strong vanilla odor is offensive. I also keep debonder handy in case of any mishaps. In fact, I really suggest that people keep debonder in the medicine cabinet for emergencies, especially if you have mischievous children.
Tom