Parabeam?

[13AL]

Is anyone using this product. How dose it stack up to the likes of Dyvinacell, Nidacoror or coosaboard. Price, strength and other factors?

[yipster]

there are those in favor and others dont like the core, i thought it certainly was interesting but dont have all the answers but was told it is often used in catamarans
Parabeam

[jimm]

I have used it in the production of 50 Dinghies. It is a strong light core when properly wetted out. The greatest advantage is it is no more difficult to lay up than a layer of glass cloth. For ultimate strength it is imperative that additional matt or cloth be added to the inter and outer skins.It also requires a high percent of hardener to kick off properly. I used the two thinnest weaves with great success.

[Neil Marine]

I met with the manufacture at the METS held in Amsterdam and I must say I was impressed with the product claims and also the ease of use. I have not yet conducted my own testing but hope to do so in the near future...from my understanding this will work great for components such as hatches and side panels.

[13AL]

Have any of you infused with this?

[jimm]

This material can not be infused or vacuum formed. It relies on a natural expansion of the vertical fibers during wet out. This is what gives it a core of vertical fibers. It is so easy to layup and control you don't need to complicate it with extra cost and labor. My 12' sailboat hull and deck went from 130 lbs to 70 lbs. and was much stiffer.

[Herman]

I have used it extensively in a couple of racing dinghies, for bulkheads and stringers, and I would never do it again. Unless you beef it up with more then desired laminate, it will show skin buckling very rapidly, due to very limited compression strength.
After a season or so of sailing, the boats made "crushing" noises when loaded. Not a good sign. (I have stood on their demo panel at METS as well, and the same noises came up. The salesperson said it was normal)

The versions I have used were done with epoxy resin, heat cured, and gave 10 and 12mm results. They had extra laminate on both sides, 300 grams / side I believe.

For what I know now I would prefer using a lightweight foam with glass and epoxy, or carbon and balsa if high stiffness at low weight is desired. Even Cork (Corkore) is a valid option.

If you use parabeam, then please use a low styrene polyester, or epoxy. Too high styrene level in the cavity can inhibit cure of the polyester, and then you have a problem.

For infusion I would suggest either a foam, balsa, or Lantor Soric, of if you need a semi-compressible core, Lantor "Lancore" or Structiso is an option.

[jimm]

Herman,
I did panel tests using various resins and found the GP resin worked the best for my applications. Perhaps it was because it was not as brittle as the epoxy and vynelester panels. Perhaps in all applications the surfaces were compound and not flat. I do agree extra laminate both sides is essential. The 8' dinghy( sides,seats, & bottom - Parabeam) is now on it's 10 year of use and has not shown the signs of crushing or buckling you describe. Is it the lightest, strongest, cheapest, construction? no it's not. It is easy hand layup.

[Pieta]

Originally Posted by jimm

Herman,
Is it the lightest, strongest, cheapest, construction? no it's not. .

You shouldnt have said that. Now I just HAVE to know what is the lightest, strongest, cheapest construction?

[jimm]

As you all ready know there is on one construction that will do all three. Evaluating those three qualities would vary with the knowledge, manpower, facilities, supplier connections, and end use of the construction as to which one or ones are right for the task at hand. The lightest and strongest applications I am aware of being used today would be infusing epoxy carbon & Kevlar in the construction of exotic one off cars ($1M). At Lazzara Yachts we started infusing (small) parts 10' x20' and saw a 40 percent reduction in weight, but it was a much more expensive process than hand layup. They have been successfully vacuum bagging their hulls (76' to 120') with balsa cores since their inception. Lighter than hand layup cheaper and stronger (tear strength) than foam cores. $4M to $17M you can afford to do it and the return in performance is substantial.
In my small shop I was successful using the Parabeam. and since it required no more effort than laying down a layer of 8 oz. cloth and reduced the weight from125-130 lbs. to 70 lbs it was right for me. I also successfully used 1/4" Kledgecell in my 16' tunnel hull for an all up weight of under 500lbs. including mast and sails. It unlike Divinicell would soften when wet out and conform more readily to contours with fewer chance of voids. Vacuum bagging would have been the next step here.
I haven't answered your question cause I don't have a answer.

[Pieta]

Hi Jimm, thanks for the reply. Yes, I am a Parabeam fan. I am also a wood fan. Dang, if 3ply was transparent?.. I would use it as a windscreen in my aircraft designs I am not a boating man but find the techniques used by you guys are very informative for me.
Greetings from South Africa.

[jimm]

Pieta,
Yes, wood and windscreens! two exciting processes. I still have my copy of 'the Gougeon Brothers on boat construction' fascinating,and wind screen designs I did on 30' to 116' mega yachts. A world of things to know. Right? Knowledge is a never ending process and I find it a rush! Aircraft design must be a real rush!
My best to you and enjoy.