I can not get my damn bags to seal. I’m doing envelope style, do both sides and seal up the top when the part is in and ready to go.
Stupid question, are you guys using the sealent tape on both sides? I just can’t seem to get this thing to seal correctly. The mold is small, no sharp edges or anything that is puncturing the bag. The leaks seem to be from the edges and where the feed lines go in, but nothing I do gets it 100% sealed.
If it’s a small bag, try sealing one up with just breather material inside and see if you get it to work. There may be a problem with something else that is leaking. I don’t know what your bagging material is, but cheap poly material from home improvement stores is notorious for having pin holes in it.
I got the material from evan, so it better be good 
I’m going to try again in the morning. Nothing I have touched has worked for me today, so I’m just calling it quits and starting fresh tomorrow LOL.
Try using a pinch roller for a window screen at Home Depot or other hardware store.
How old is your sealant tape?
Double up the corners and over lap the jointing seams.
Tape is brand new. I’ll see if I can dig up a screen roller today, good idea.
Just wondering, I had this old as-seen on TV thing from years back. It was a bag sealer for chips and stuff. It has a thin metal wire inside a “clip” that is heated when you press down and run it across the surface of plastic. It would seal a ziplock bag in half, no leaks.
Wonder if something like that would work as well? maybe not 
Can you take a picture of what you did?
Just wondering, I had this old as-seen on TV thing from years back. It was a bag sealer for chips and stuff. It has a thin metal wire inside a “clip” that is heated when you press down and run it across the surface of plastic. It would seal a ziplock bag in half, no leaks.
Wonder if something like that would work as well? maybe not :)[/quote]
I have one of those on the refer. in the kitchen…I doubt it but just last week I gave Evan a catalog that had foot operated bag sealers (much bigger and a wider sealed strip) and other heavy duty euipment that may work for this subject matter: www.abbeon.com I think is the link to them.
JM
Evan,
I threw the bag out last night, I had a bad night hehe.
Do you use tape on both sides of the bag, and press them together? That is what I was doing.
I’m going to try again later tonight or tomorrow morning, hopefully with better results. If I still run into a snag, I’ll take a pic for you guys to show me what I’m doing wrong.
Thanks
James
You don’t need to use the tape on both sides. I’ll take some pictures tomorrow when I get back to the shop.
Do you fold the tape over? I’m going to make another bag shortly
Ok I forgot to bring the camera, but I found an old pic that will help. Hopefully.
As you can see I folded the bag in two, when making an envelop bag, then lay the tape down along the 3 edges. Then I flip the other side of the bag around, peel off the paper one edge at a time and join the top and bottom side together.
So, tape goes in the center?
bag (top)
TAPE
bag (bottom)
It’s kinda hard to see from the pic, but it looks like plastic is on the outside of the tape.
Thanks!
James
Yes the tape goes between both sides of the bag. cut a bag twice the size of the part to be vacuumed. Take Evan’s peice for example, lay the part on the table and then lay a bag over it then fold it over a second time to create an envelope. Now lay it out flat and apply sealant tape to the bottom half. See picture. Don’t remove the paper yet. Now fold the bag over the bottom half and pull the paper slowly while sealing the bag together one side at a time. I recommend doing one of the small sides and the long edge. Now put your part in and finish sealing the last side.
note: the above is for an envelope bag. for Evan’s part seeing as it is pretty much flat I would actually seal the bag to the table. Take your time pulling the paper off the tape while sealing the bag. No need to rush if you’re infusing.
I have found that simply using some silicone sealant and a cheap caulk gun works wonders. You can seal a whole lot of bags for $3.00, it is way easier than trying to keep the bag from accidentally sticking to sealant tape, and another incidental advantage (of using a colored variant) is that it ‘runs’ where there are pinhole leaks; you see a small trace leak, and just pinch some silicone from a side towards the leak to close it off.
Good luck
I’ve tried all weekend with zero success. Using the methods here, I still get a slow leak somewhere in the bag. I’ve done several bags, all of them fail with different molds. The edges seem to seal up fine, and I cannot find any leaks but it still loses vac slowly. I checked the bag over and over again but never could hear any leaks, it’s so slow that you don’t even hear the “crinkle” of the bag reinflating as with larger leaks. At this point I’m thinking there may be issues with this baging material itself.
What else is this sealant tape used for? The grey double sided stuff, I wanted to see if I can find more locally since I’m out 
How are you making your connection? It’s hard to diagnose without seeing what you’re doing exactly. If you want to know for sure, go thrown down some money on an ultrasonic leak detector.
Connections are via 1/4th OD tube, and I’ve also moved up to 3/8th OD as well for vac line, pump doesn’t have to work as hard. T-barb fitting in the bag has some sealant tape around the tip. Puncture through the bag and fit the tube. I seal up around the end up the tube just to be sure of no leaks. The bags are envelope style with the grey sealant tape in between the layers.
Unfortunetly I have no pics. I made several bags based on what i’ve read/seen from various sites and this thread Now I’m out of tape, so the fun has to stop for a while
I’ve just had a bad week period, nothing has worked right carbon wise. On the flip side, anything metal working wise has turned out excellent. I guess it will even out eventually hehehe
I doubt the use of a “T” fitting in place of a regural vacuum baging fitting (these are cheap) would work correctly. JM
JM,
we use t-fittings in vacuum infusion because they’re disposable. @ $15-20 a piece the regular vacuum bag fitting doesn’t become so cheap anymore. I know you can clean out the resin if it gets into the fitting, but you can’t do it any more than 3-4 times before the whole thing is clogged up and become useless.