Hi Don Ricardo, I used my excellent vision and a bit of Googling to work out that it is not actually S.I.S. but S.1.S. (S.one.S.) which stands for `Smooth on One Side'. There is also another term S.2.S. which strangely means `Smooth on Two Sides'
For caravan construction S.1.S. board would be quite suitable and what you would expect to find. Now ends the lesson
In response to the questions raised in the posts above this one, here are my best guesstimates.
If any of our 3546 members have expertise in this area please jump in and contribute …. or forever hold your peace . Remember we are trying to learn about the way plywood was graded in 'Vintage days'..pre 1970. I have not been able to find how marine ply was designated in vintage days.
Taken from a condensed version of the grading systems as described in the September 1953 edition of 'Popular Science' magazine, I am fairly sure it is an American edition... It does mention a few different systems of what I think is the American way of grading plywood (back in those days at least) but as one of these systems have been found on Australian built caravans I think it is worth repeating here.
It starts off with grades marked as 'G2S' and 'G1S' indicating 'Good two sides' and 'Good one side' I don't think we have seen that system on ply used on Australian vintage vans yet ?
The next system described uses the 'S2S' and 'S1S' method, indicating 'Sound (or Smooth) two sides' or 'Smooth one side'. This system has been used on at least three members vintage caravans. This system doesn't appear to accommodate grades other than those two above, instead they move on to the two mentioned next.
The two other grades described are 'WB' = wall board grade with a sound face and utility back and 'SH' = sheathing ply, has two utility faces and is un-sanded.
Another system described is closer to what we are familiar with...A.B.C.& D. where a panel marked A A indicates two good faces... A B = one good face and one not so good.. A C = one good face and one utility face... lesser grades would be marked C D or even D D.
Anyway, corrections and/or additions to the above are very welcome.
Australian plywood manufacture commenced in Melbourne in 1911 but the two plants closed after a few years of operation. Around 1914 plywood manufacture commenced in Woolloongabba, Brisbane. Thereafter Brisbane became the main centre of plywood manufacturing activity with the 10 mills producing about two thirds of all Australian production, thus making this city the logical base for the Plywood Association of Australia. The Australian industry expanded around the country after the second World War to the stage where in 1960 there were 63 mills. Around this time the local industry was under threat from imports, and other panel products, so the industry invested heavily in CSIRO research to better understand the manufacturing process and improve productivity. In 1960 the mills used timber from indigenous forests with around 80% of the production being for interior use. Today, the nine, on average much larger mills use mainly plantation timber with around 90% of the plywood produced being for structural applications.
I took a long shot and sent the EWPAA a email asking if they can help with any history regarding plywood manufacture in Australia. Well I received a prompt reply from a gentleman who seems to have a bit of interest and he has asked me to send him photos and information on any marks found on plywood and he will do the research on them for us. Didn't really expect any reply so I think that I should take this guy up on his offer........may not go anywhere but potentially it may help to date some vans. Trouble is right now I don't have the time to pull the information together from the various posts and I don't want to let the contact go stale. So is there anyone who has the time to do the time do this and either reply on my behalf or send it to me by email???
Plywood brand on Dosses “Mabel” Brown & Board were a subsidiary company of Josias Hancock of the Hancock and Gore firm and started producing plywood about 1930..... they were timber merchants and house builders prior to then.
There is more information about plywood manufacture in Australia HERE.
Thanks for drawing our attention to that 1954 advertisement, I wonder what the trade mark looked like in 1954 ? It may not have been different to the one shown on dosses van that looks like a late 40s or early 50s van.
I'll update my original ""Wresply" post with the new info
Hi sorry if this is a little off topic but i am trying to find more info on a golden fleece road map display and the only info on it was a stamp on the back Bulldog Brand Hancock & Gore so from what i have seen hear that would just be the company that supplied the wood for the display and the logo was different again in 1966 (date of the Map only reference to age of display) DISPLAY: LOGO: Cheers
Thanks for dropping by and thanks for showing us the octagonal Hancock & Gore trade mark, we haven't seen that shape before and you would think it would be relatively easy to find out when it first appeared ..... so we'll work on it, starting around 1966 which is the date on the Golden Fleece map which, as you would realise, may or may not be a good clue, I reckon it's a good clue so thanks for posting it 😉
Ken Koala and I have put a bit of effort (and time) into researching trade marks but I think it is fair to say we kept running into dead ends. I have seen that Bulldog on that IPAustralia link you gave us but, from memory, I don't think I was able to find any of the bull dog heads we are familiar with, or maybe I just gave up 🙄 In previous posts on this thread I have noted a couple of sources to the general history on plywood manufacture in Australia hoping it might inspire somebody to help with research, but I generally post them as hyperlinks (there I've done it again 😩 )which may not be a good idea because not everybody bothers to click on hyperlinks. But if you are fascinated by bond wood trademarks and would like to spend some time researching them your efforts will be highly appreciated and well rewarded 😘
Got the following reply from Hancock & Gore - unfortunately no joy for us.
Sounds interesting – I’ve only been at the company a couple of years, and knew that we started as a timber business, but you never really know what the products were used for. I’d have never thought of caravans I must admit!
Unfortunately, we sold the timber interests back in the early 1980’s, and the records from that business have been destroyed in line with standard business practice, so I can’t provide any information that may help you.
I hope you can find alternate sources of the information.
IAIN THOMPSON CFO / COMPANY SECRETARY
HGL Limited Level 2, 68-72 Waterloo Rd, Macquarie Park 2113