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Epoxy foam

  • 10 Sep 2026 16:34
    Quote
    Reply # 13688924 on 13687882
    Anonymous member

    To Frank :

    Hi Frank!

    I’m curious how long ago you used this additive ? If it was more than a year ago, did you notice any deterioration in properties of this additive after that time (the product description lists a one-year shelf life)?

    As I understand it, you add this agent at a ratio of about 0.5-4% to the base resin, mix it thoroughly, and then mix the whole thing with the hardener? That sounds like exactly the sort of thing that’s right up my alley!


     I don't know how long we had this sitting around unused. I haven't noticed any deterioration in its properties. However, the way I/we use it is not very scientific, nor is it for high-performance or critical parts. I most likely wouldn't even notice a 50% decrease in foaming performance.     

     Just mix the resin and hardener as you normally would, then add ~4% of the total weight. This should result in a volume increase of 200–300%. It is also possible to add a thixotropic agent ("a better foam-up and a more homogeneous foam structure"), but I haven't tested that. The technical data sheet is very good:

    https://www.hp-textiles.com/TDS/EN/Fillers_Additive/HP-BEL_Series/GTDS.pdf

  • 10 Sep 2026 00:07
    Quote
    Reply # 13687882 on 13683295
    Anonymous member

    To Eric:

    Hi Erik! 

    Thanks for the information.

    Since SICOMIN sells various types of epoxy foams, I’m curious which resin (and hardener) you use and whether you happen to know their shelf life before and after the package has been opened.

    Regards - Jan

    To Frank :

    Hi Frank!

    That option (the HP-BEL11 foaming additive) sounds the most interesting!

    I’m curious how long ago you used this additive ? If it was more than a year ago, did you notice any deterioration in properties of this additive after that time (the product description lists a one-year shelf life)?

    As I understand it, you add this agent at a ratio of about 0.5-4% to the base resin, mix it thoroughly, and then mix the whole thing with the hardener? That sounds like exactly the sort of thing that’s right up my alley!

    Regards - Jan

    Last modified: 10 Sep 2026 10:03 | Anonymous member
  • 09 Sep 2026 15:16
    Quote
    Reply # 13687090 on 13683295
    Anonymous member (Administrator)

    Bonjour

    Sicomin is a reference in France and there products,are largely used by shipyards... I hygky recommand. They are my epoxy providers.

    They are specialysed into Epoxy and there products are easy to use with a great technical support.

    I've used some epoxy foam to full up a keel bock. It as very good mechanical property. It has closed bulled ans are so completly watter resistent.

    The epoxy foam is for example used to fill up the space between the rudder skin and the rudder stroke (JPK).

    If you use to largres benches the temperature will rise and the product may have mon optimum caracteristics.

    There are several density of epoxy foams with more or less gaz into the foam.

    Eric
  • 07 Sep 2026 10:31
    Quote
    Reply # 13683852 on 13683295
    Anonymous member

    Hi Frank!

    Thanks for the link. This kit looks (and costs) very interesting. The shipping cost is a bit of a problem. For now, I'll keep looking in my country. 

    The problem is that this type of foam isn't as popular as others. I only wanted to do a few experiments for now, so such a small kit is really attractive. Others offer much larger and more expensive kits. 

    Since I'm a complete novice with foams, I'm wondering if I shouldn't start with more popular foams. I have an idea for an unusual "honeycomb" composite with roving, so maybe regular foam from the supermarket will give me some initial insight. 

    Experimenting with foam seems to generate a lot of waste, so small quantities are fine.

    Regards- Jan

    But wait! I must have misread! Is this just a foaming agent? So you add it to regular resin and it creates foam? That's even more interesting than I thought! 

    Regards  - Jan

    Last modified: 07 Sep 2026 11:18 | Anonymous member
  • 07 Sep 2026 08:07
    Quote
    Reply # 13683777 on 13683295
    Anonymous member

    Hi Jan,

    I used this foaming agent to fill the space around the deadwood inside my keel. 

    I also used it to repair wet and damaged jefa like rudders. It doesn't expand as much as other foams, but it also generates almost no pressure so that you don't have the problem of the foam pushing parts apart.

    https://shop.hp-textiles.com/shop/en/Liquid-foaming-agent-HP-BEL11.html

    Best 

    Frank

    Last modified: 07 Sep 2026 08:10 | Anonymous member
  • 06 Sep 2026 19:54
    Quote
    Reply # 13683321 on 13683295
    Anonymous member

    Edvard, it's very kind of you to share your knowledge of epoxy foam with us. Did you save any photos of the stern repair in your "Freedom 30"? If you plan to post such photos, I recommend the "attach file" function (at the bottom of the editing window).

    I've noticed that some customers of the shop you mentioned claim they get much less foam and that it should be poured in small batches. Have you had similar experiences?

    I wonder how long you've been sailing with this new stern, and if you have any way to check if the foam still doesn't absorb water?

    Best regards, Jan.

    PS  I also found another technique.

    Last modified: 06 Sep 2026 21:10 | Anonymous member
  • 06 Sep 2026 19:12
    Quote
    Message # 13683295
    Anonymous member

    I created this thread ("epoxy foam") as  "fork" for the   thread "Freedom 30 car ketch ...")


    hi jan

    Jan Czaplinski wrote:

    …I'm intrigued by the name "epoxy foam."

     Is it the same as "two-component PU pour foam"? Or is it a different type of material?

    i found this (amongst other results) with a short web search. (i didn’t know epox foam either…)

    ueli


    Thanks for the reply, Ueli! 

    I found this site too. I've been trying to familiarize myself with foam technology lately.  I'm not a chemist, but it seems to me that epoxy foam would be a very interesting product.

     Unfortunately, there's not much information on this website.  So I'm wondering if epoxy foam isn't simply two-component polyurethane foam being sold under the name epoxy foam.

    Jan

    EDIT (one day later): But—maybe not? I'll continue to research the topic...

    EDIT2: link (from Edvard) to the shop in NL

    Last modified: 06 Sep 2026 20:18 | Anonymous member
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