Cougar -

I “think” what you are suggesting/trying to do is what NACRA catamarans calls their “Infusion” process. I’m not positive, nor have I looked into the technology - but for a while, they were advertising the process in the advertisments for both their Formula 18 and their Nacra 20 cats.

Here is link to more info on the “Infusion” process.

Again - not sure if this is what you meant? Dick

After all, if when lamitaing you use 3 to 4 thinner cloth layers, and each one fo them will cover the whole mold, the final result will be a very even thickness.

Tato Lazo

1/ The principle or methodology for that matter is not the same…one uses force and the other uses vacuum.
2/ Yes we are using vacuum, and vacuum is correct terminology,now you could argue that talking in atmospheric values is actually correct , neither of us would be wrong but for the layman to understand simple terms are often easier. so to be clear ; it is not negative pressure inside the bag - there is no such thing,when you even induce -1 kpa from a potential -101.5 kpa then you have created a vacuum…granted not a full vacuum but i can assure you it is not negative pressure inside the bag…
3/ Partial vacuum may imply a reference to particulate’s to some but common everyday language uses “partial” as a descriptive term…ie…part thereof.
4/ Given that I am picking you are either a treky or a rocket scientist and given our line of business downunder we could probably debate semantics all day long…in fact I would enjoy meeting you, I think you would enjoy playing in our pressure/ vacuum calibration laboratory.

Cheers …Gary

Cougar, here’s a idea for a vacuum pump , I built one many years ago and built some really big components with it (car panels) and it was incredibly reliable, total cost around $40 US and most of that cost is in buying a reasonably good analogue vacuum gauge buy one with a 63mm dial face minimum size. Buy euro or north american manufactured gauge only , these typically have an accuracy class of 1.6% of full scale value…cheap chinese gauges and gauges smaller than 63mm will drop to 3 or even 4 % accuracy of FSV… are not reliable and have poor readability.

Go to a business that repairs commercial fridges and you will likely find a stack of dead refridgerators that they will be happy for you to remove the compressor…gratis. …this is how i got my hands on as many as i wanted.


is it realy hard to build a vacume bagger? i know that sounds like a dumb question… but i got a small fridge here. that the temp is toast… either freezing. of defrost… i can use that…
so i got the pump… now need a gauge… this could be an easy build???or is it going to get compliacted

It’s pretty simple. A bag large enough to fit your hull, some release film (kind of re-usable) some peel ply, some breather fabric (or paper towels) the fitting to attach the hose to the bag, a way to seal the bag after you place your layup in it, the hose (valve and gauge if you want) and your pump. See the paper above to modify your refrig compressor. You can get it all from most composite suppliers.

Sounds like a lot of stuff, but not really. The first time I tried, I taped a plastic bag closed around my mold, poked a hole in it, slid the hose in and wrapped tape around it to seal, and turned the pump on. Worked like a charm! I did buy the release film and breather.

Since then I have purchased some better (read easier to use and re-usable) materials.

Gary (Morspeed), yes, we could debate the semantics but I’m conscious that our ‘conversation’ is distracting from Cougar’s question so let me just say that I’m neither a treky nor a rocket science but do have a good grounding in physics and, yes, I would enjoy meeting you (and many others on this forum).

Cougar, yes, a basic vacuum bagging system really is quite simple to set up and very effective in producing consistent laminates. One thing to be aware of, assuming the rest of the world is like the UK, the disposal of refrigerators is now tightly controlled because of the potentially harmful refrigerants they contain and I don’t know if it is quite as easy to get hold of a used pump?


i got my hands on a small bar fridge… and in the process of taking off the compressor… when i get back from my vaction… i am going to get together with a group of guys… each one given a task… and seeing what we can learn from each other… a vacume bagger is one of the tasks… as well as master , molds , sails, rig, bulb ect

i hope the small compressor will provide enough