I've new information about gluing Coroplast
After reading this page, Rick Webber, UK sent me the following email. Many thanks to Richard Webber for sharing.
Bonding Coroplas / Corex
Many years ago (2002) I was making and selling many SPAD aircraft kits and I had very little success with flashing and CA which was the recommended method at that time.
My solution was to contact an adhesive manufacturer in my local city and challenged them to bond some sample corex that I sent them.
Within two weeks they returned me a sample bottle of a CA they code named SF100 (Now available from 3M), along with my corex samples well and truly bonded, in fact one of the planes made back then with SF-100 is still flying today without any problems.
I, like you test the bonds to destruction and in all cases the corex surface was ripped to shreds with large chunks still bonded to the other test part.
The method used to create such a strong and lasting joint only requires the corex, (both parts), to be cleaned with methylated spirit and allowed to evaporate prior to putting spots of adhesive every half to three quarter inch onto one surface, place the two surfaces together and apply even pressure along the length of the join.
I am aware that 3m Scotch-Weld SF-100 is not a cheep adhesive but it really does the job as long as it is fresh and stored at low temperature out of direct sunlight.
Hope this is of interest
Testing Glues on polypropylene
- CA Glue ie Grazy Glue, Superglue, cyanoacrylate. This brand is a low end brand from the hardware store.
High end CA glue by Loctite 406 is reported as a good glue for this but I wanted to check out a lower end and much less expensive glue.
- Contact Cement, from the hardware store.
- 3M Specialized Hot Melt Glue. This glue gets very hot.
- Regular hot melt glue sold for more demanding applications. The temperature is in between the 2 grades.
- Craft grade hot melt glue which actually melts at quite a low temperature.
- Polyurethane construction Adhesive. Lepage's Premium PL
- The cheap cyanoacrylate (super glue) made a strong glue bond which would not come apart after energetic pulling. I eventually managed to separate the 2 pieces by twisting them apart. I found that only about half of the sample was glued. The rest was still wet. I think I had put too much glue to start. Impressive result from a smaller area.
- Contact cement glued but was relatively easy to remove. I would call this a suitable tacking bond if I was planning to sew or wire the sections as well as glue. Good for positioning. It would stay together if no stress was placed on the bond.
- 3M Specialized Hot Melt Glue stuck absolutely and I was not able to remove the pieces. The polypropylene tore rather than let go. After a week I was able to tear the 2 pieces apart but some of the plastic was torn.
- Hot melt glue came off after a hard pull. It worked but not well. It came off equally well from both surface with bits of glue left on both surfaces.
- Craft grade lower melt glue was much harder to remove than the so called heavy duty medium heat glue. Also most of the glue was left on one side showing that application method had an impact. I was able to eventually remove it but it took some force to peel it off.
- Polyurethane construction Adhesive. Lepage's Premium PL did not hold at all and peeled off. I checked the piece I had kept aside and it also flaked off with no effort required.
NOTE: Although I did not test it personally, 3M Scotch-Weld SF-100 has been reported as completely successful, see letter at top of page. Amazon.com can supply it, I have a link on the side links. It is pricey and it works.