TOPIC: hand-laid fiberglas.......

does any one know what manufacturers of finned boats back in the 50's and 60's, were hand-laid fiberglas??? ron

I could be wrong but I thought all the boats in the 50s where handlaid and most of the ones in the 60s as well.

Yeah I was thinking that same thing.

Bob

What are the advantages or disadvantages of "hand laid" as opposed to "vacuum formed" when it comes to fiberglass?

I don't think chopper guns came into play till sometime in the 70's so 60's for sure where hand laid most 70's were too 80's ya gotta be careful a mixed bag of both depending on builder.
MFG would have been notably different where they formed the hulls using sheets of stranded mat
between two steel dies one forming the outside of the hull, the other the inside of the hull and sucked colored resin in. Then it was cured at a high temp. Much the way corvette body panels and the old cafeteria trays and chairs where made. This maybe what you are referring to on vacuum formed. In my mind it's a phenomenal way to do glass but also very expensive tooling for such large molded pieces so not really adopted widely for boats.
There is another method called vacuum bagging a lot of custom hi performance builders use this today.
Please forgive me if I miss critical details but the basic idea is to compress the laminate, remove air and get uniform resin through out the laminate. The whole cloth laminate and mold kit and ka boodle is put into a plastic bag and a vacuum is pulled on it, this pulls the air out of the laminate and the outside atmosphere pushes down on it uniformly to compress it against the mold. The resin can be applied being drawn in and wicking through the laminate under the vacuum, generally this minimizes the amount of resin needed so a lighter weight more uniform laminate results. Strength comes from the glass fibers not the resin so any excess resin just adds weight with minimal strength increase. A modified version of the method is to apply the resin prior to bagging and pulling the vacuum. You tube has many video clips of this being done.
Randy

Larson Boat Works of Little Falls, Minnesota first used the “Rand Gun” chopper in 1957. They were working with Ingersoll-Rand Company in the development of this first mix/chopper. What it did was cut a continuous strand of fiberglass to whatever length you required, mix the resin and catalyst, and blow this mixture into the mold at a set air pressure. At first they had exclusive rights to use this apparatus, but soon other manufacturers got in on the deal. The patent was applied for in 1954 and was published in 1957 and was awarded to David F. Anderson, assignor to Canadian Ingersoll-Rand Company Ltd. Larson used to put a small decal on their dashboards declaring that the boat was built under U.S. Patent No. US2787314. The use of the gun greatly reduced the time spent laying the fiberglass up in the mold, increasing production. By the early sixties most all of the manufacturers were using the guns, in one form or the other. The smaller manufacturers continued to use the hand layup process, as the equipment was quite an investment. Binks Manufacturing Company were quick to follow on the Rand Gun concept with a similar product. Quality issues? That depended greatly on who was manning the gun. I worked for a fiberglass manufacturing company in the late sixties and the operator made all the difference in the world. A lot of people thought that they knew what they were doing, but were nothing more than “gun pointers.” You had to get the mix correct, lay the mixture evenly, and have skilled rollers in place to lay the mat down. People today seem to believe that hand layup produces a superior product due to the horror stories out there concerning chopper guns, but it was all dependent on the operator and the specifications used by the manufacturer. MFG, of course was the exception with their die formed hulls. With the investment required in tooling, as well as a 750 ton hydraulic press, this process was way beyond the capabilities for most manufacturers. The Aircraft Division of GoodYear also produced a die formed hull that was used by Bowman, out of Little Rock. I believe that they also used this hull in their early Geneva boat line. Very similar to the VEC technology used today by Larson boats. Nothing new, just a replay from the past.

Lee Wangstad

from a 1959 red fish owners manual

thanks for the replies. i had heard that the hulls of the hand-laid fiberglas boats were much stronger than the chopper gun method..now i know thanks again

Hello Lee,

Thanks for history lesson. All great information. And like anything else the results of the finished product depends on who is working the tools.

I saw a 57 Glasspar Avalon recently that had gash in the hull below the floor. Upon closer inspection it was evident that the matting was not properly overlapped at that location.


Hope to see you soon. Maybe at Racine in September?
Terry

About 1957 Owens Corning came to us at Power Cat to demo their fiberglass construction products. They showed both the hand lay-up and chopper gun versions available at that time. Power Cat made our first fiberglass boat in 1958 using the hand lay-up system and continued with that through the last years of the company.

...and thanks to Powercat, I can crawl up under the deck of my 15T without getting stabbed by chopper gun prickly strands everywhere.

Thank you Powercat for quality hand laid glasswork...I have loved Powercats since my Dad bought one in 1966...now I have a matching 1965 after searching half a lifetime!