Foam protection ?

[B J StalParticipant @bjstal88383]

Putting together ideas and plans for an actual work boat. I will use it on a river and it will carry a depth sounder. It will go ahead of me in shallow water. I will be behind it in a normal boat and it will hopefully help keep me out of trouble. — Planning on an RC air boat because of weeds, and somewhere around two feet long. Thinking about using block, blue foam. Question; Can this material be sprayed with a rattle can paint to give it a little bit of a skin, for a little extra protection and strength? ? If so what type? Are there otther better types of foam, or what ? —- Thanks for any and all thoughts.

[B J StalParticipant @bjstal88383]

[ashley needhamParticipant @ashleyneedham69188]

Ho BJ and welcome to the forum.

I presume you mean Blue Styrofoam? You should be alright with this for your boat.

​Toughening up the skin can be achieved by using Eze-Kote, which is an acrylic resin, and fine class cloth.

​Alternatively J-cloths instead of glass cloth work very well, they are very tough and cheap and come in a variety of fetching colours. PROBABLY any acrylic varnish will do realistically, but do not use polyester resin as this will melt the foam. Epoxy resin is fine.

​Spray cans all ok to use AFTER the foam has been painted with acrylic.

If that's you on the RC forum, the advice there seems to be good, and of course includes trade names I have not heard of!

Ashley

Edited By ashley needham on 16/03/2018 09:34:57

[B J StalParticipant @bjstal88383]

Thanks, Ashley

Good information.

Checked over at RC forum and found one on "Painting Foam". Not me, however yes there is some good info. there. Thanks for that lead.

Building a forward looking sonar, but that will take quite a long time. Hopefully this little guy will help me find the holes and shallows, and keep me out of trouble while I am looking for that elusive fish. Just moved and have a new river to learn.

Thanks again

[B J StalParticipant @bjstal88383]

 

More Q. Ashley

 

Good info, but leaves me with a couple questions.

 

You refer to fine class cloth. Not sure just what you at referring to. Just regular cloth material? Like cotton fabric or what? Maybe nylon?

 

You mention J-cloth. Do you mean the product used primarily for cleaning. Is that very thin, and will it come as a smooth and finished skin on Styrofoam?

I have some 2 inch blocks of Styrofoam I need to glue together. What is the best way for strength? Spray like 3M has, or the brush-on like some others?

 

Thanks again for your help.

[ashley needhamParticipant @ashleyneedham69188]

BJ.
​Fibreglass for moulding/whatever comes in two main forms. Chopped strand or woven.

​The chopped stuff is just that, glass strands chopped up to short lengths and rolled together with a bondinmg agent to make sheets (the bonding agent keeps it together and melts with the resin). OR

​Woven, which is just like cloth, and comes in various thicknesses from stuff like silk stockings up to sacking. The very fine stuff conforms to curves like Mae west`s bodice (sorry I used that elsewhere) and is useful as it really does drape round even tight curves.

J-Cloths. Yes, the cleaning cloths. They are very tough and yes they will not be as smooth after application, but you are not building a racing boat. After three applications of resin I should think they would be smooth enough. Trevor here at the pond used J-cloths to make a tube for a motor housing and we were well impressed, and I will be using it for internal reinforcing when the time comes for such things.

ALTERNATIVLY, probably simply painting the surfaces with PVA glue, say three coats would provide you with sufficient protection…no cloth or anything else…actually, using J-cloths and PVA would be a really good cheap covering, not hard like resin, but bump-proof. It would not crack like thin glass coverings either, a point to consider.

​Gorilla glue, the foaming stuff works really well and is economic for use on large surfaces. Epoxy is great but you would need quite a bit and then it becomes expensive. You do have to make sire the foam cannot move when using Gorilla glue as it does push the bits apart when foaming up.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

As an afterthought, and not the cheapest option, but if you had a foam airboat (or for that matter any other suitably shaped craft), and were able to temporarily fill it with foam blocks so it didn't collapse under the vacuum process, then taking it to a vac-form person and having a very thin shell of styrene vac-formed over the hull would result in a nice smooth finish. The foam would be left in place of course, the styrene would likely have been heat bonded to the foam. I am not talking about making a hollow vac-form moulding ( like the Farman) .

Just an option.

​Ashley

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