vacuum pump size

The excess resin comes of with the infusion medium.

Try and always use perf. film. Below the perf film you optionally use peelply. This way you can always easily remove the infusion medium (and the perf film with it) and in areas where you have the peelply, you can leave it there, if desired. This will protect the surface from debris and foot traffic. Remove it just prior to further laminating, gluing or coating. Very usefull for insides of hulls, which see a lot of traffic and thus pollution during the further build.

About Soric: Great product. This product makes it possible to infuse without infusion mesh, and without the weight penalty of other "stay-in-the-laminate" distribution mediums.

2 things to watch for, though:

-1. You cannot control the infusion strategy as much as with a setup using mesh and runners. (not important for square panels and similar)
-2. You must make a resin entry into the Soric. So at your resin inlet, you should have the soric exposed, not buried under layers of glass.

Depending on the type of soric, expect to use 600-700 grams of resin per square meter, per mm thickness. (sorry, not used to imperial units that much)

One other thing which I discovered, and which is not (yet) in the datasheet:
After having pulled a vacuum, leave the Soric under vacuum for at least 30 minutes, preferably a bit longer. This will make the trapped air in the balloons of which the Soric is made to escape as well. Failing to do so will give you a laminate with air-filled soric channels, instead of resin filled...

They will include that in the datasheet, but I have no idea if they have done that yet.

 

I finally got some vacuum guages. They draw to 75 kPa (out of 100) with the dry vein pumps I have. How good or bad is this ?

Another concern is the vein pumps gets very hot if I block the air to draw the maximum vacuum it can. Is this normal ?

Had a power out due to unexpected hail. Mental note - keep a generator handy.

 

How hot is hot? An oil lubricated vane pump gets amazingly hot. (do not hold your hand on it, it will be approx 80 degrees C). Just make sure the electric motor gets ventilation.

-0,75 is not bad. Could have been better, but is very doable.

If the hail was expected, would power have been lost as well? Indeed: keep a (working) generator at hand...

 

Hi Herman,

I could still hold my hand on the pump area, and the motor is not hot at all. The little air that is puffed out is very hot, I can just imagine how hot the veins must be getting.

I have other vein pumps, a different make, I'll put them up and see if I get a better vacuum, maybe use them instead.

What is worst case, and what is considered good ? 100%

I was thinking of having a 'portable' vacuum pump for areas where air is trapped in. Stick a needle in the trapped air part and vacuum the pocket out, patch the hole with tape when done. Could this work ?

I asked for a 500kPa vacuum guage, the guy said they don't have any

 

Barrylay
Your question has already been answered nicely by Herman.
When using release film under the infusion mesh I still recommend that you use peel ply. I purchase this directly from a textile supplier at half the cost from fibreglass suppliers, here it is sold as plyester taffata. I mostly use a 60g sqm. 30% shade cloth here costs $1.70sqm where as cheapest infusion mesh is >$5sqm. Also it only wastes ~325g sqm of resin. Like any infusion mesh shade cloth will leave a very small indentation, this is not a problem and you always have one smooth side.
I use the attached file to determine the resin required for a job, it will also show you the relative costs of matterials.

 

Here is the file, cuold not attach it with quick reply

 

shade cloth

I was able to purchase shade cloth from Lowe's hardware for 34 cents a foot, it was 6 feet wide. We infused three 30 foot panels and this worked well.

Pat

 

Hey all you guys - many thanks. Lots of good information here. The scare factor is the major thing for me. I have always been afraid of large expensive flowing masses that set quickly and potentially could become a huge disaster - concrete, resin, etc. Got to plan well.

I am not yet sure that my application warrants the infusion process. I am considering doing an 18' (5.5m) stitch and glue boat, which only has one layer of glass on the exterior. If anyone is interested it is the i550 and can be seen at www.i550.org.

Why I was considering it is because of the lightness and the possibility of doing more than one boat, either two simultaneously or two sequentially. I am trying to come up with a plan to have a female mold and possibly avoid all the stitching. I am just not sure if a female mold could be made with tight enough tolerances to have all edges, chines and gunwales, meet nicely.

Any ideas?

Regards

Barry

 

http://www.boatdesign.net/forums/boat-building/minicat-5-a-24096.html

 

Andrew,

Do you have an alternative for a resin trap?

Thanks

Barry

 

If you can't find a reasonably priced paintpot to make into a resin trap a length of 4" PVC pipe and endcaps work just as well. It's the white pipe on the right. The black one is just a reservoir I used because I had it.



All you need is a 1/4" NPT tap for the fittings. Just be careful when you drill the caps you don't split the cap. Drill before gluing to the pipe. I put a screw on cap (cleanout) on the bottom. I think the total cost was $15

 

Rick,

Thanks. So how quickly will the pipe fill with resin? It looks pretty permanently fixed, not that disposable. I can't imagine being able to remove any resin even with the cleanout at the bottom.

I tried a plastic paint bucket, but it didn't hold the vacuum.

Barry

 

Hey Barry

I guess it depends on what you're infusing. I've only done small parts (2' dia). Just a few drops got to the trap. Ideally you'd get none in the trap. On large parts you'll want to stop the resin inlet when the part is about 3/4 infused and the vacuum will continue to pull the resin into the part. If you have multiple vacuum lines on large parts (best strategy) you can crimp them off before the resin hits the lines. Check out some of the videos on Youtube on infusion and you'll see them crimping off the resin lines when the part is near finished and the resin will continue to flow completing the part. It seems counterintuitive to newbies but when you think about it and try it a few times it actually works and gives you the best resin/glass ratios.

I certainly hope I never fill my resin trap! It's probably a gallon or more in capacity and that's near $100 in resin & hardener going into the trash bin. I've eventually got a 31' boat hull to infuse and controlling waste on a project that size is very important.

I greased the inside of the trap with vasolene as well as the threads to the cleanout. Nothing will stick to the inside I'm sure.

 

Barrylay

I always calculate the amount of resin required for the job with my spreadsheet, depending on the size of the job and compexity of the resin feed lines the amount of resin going into the catch pot is 100 - 300g.
Rick is correct that you stop feeding resin well before the resin front reaches the vacuum lines, if you dont you will be waisting a lot.
I use a 10L paint pressure pot because I was given an old one for free, I place a cut down plastic bucket inside to catch the resin.
The down side with this is that you can not see inside, you have to judge by weight. I was going to cut a 50mm hole in the lid and seal with a clear perspex to act as a window but never got around to it as it has not been an issue.
An alternative is to pick up an old pressure cooker from a second hand store and use this in the same manner.
Another alternative is to use a wine bottle. Before I was given the pressure pot this is all I used in fact still do at times just so that I have an excuse for drinking the stuff.
The only qualifier I make here is that the resin being used has to have low exotherm, if not the bottle may crack due to thermall stress and you will lose all of yor vacuum. So if you are unsure about your resin then do not use glass.
The other thing to make sure is that the resin inlet tube is inserted further into the bottle than the vacuum line and you could always put a couple of bottles in series for added security.

So if you can not get a hold of an old pressure pot or pressure cooker and you do not want to risk the wine bottle then make a fiberglass container by moulding over an inverted plastic bucket or a flower pot large enough so that the standard 9L bucket will fit inside. You need to incorporate a flange on top, to which you seal with a clear perspex lid ( O ring or simply tacky tape).
Connect your resin line, vacuum line and vacuum gauge to the perspex lid.
The fiberglass would have to be approx 6mm thick to whitstand 100% vacuum.

Cheers
Andrew

 

Rick and Andrew,

Thanks again. I am still unsure if I can even use an infusion process as I am going to be building a stitch and glue boat. The fiberglass would be over the plywood and I am told by Herman on this list that plywood is too porous to hold a vacuum. I was going to do a test, but maybe you also have opinions or techniques about doing that. Is it possible to do infusion on plywood?

Barry