Vaccume bagging leak

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Vaccume bagging leak

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fgayford	fgayford posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 433, Visits: 1.2K	justas (07/02/2014) I am new in infusion and would be appreciated for any advice. My though is to make boom infused from inside as there are many additional layers in some places inside. So I made a two-sided mold. I put necessary laminate on a table, just glued slightly with spry together. Then peel-ply with a reserve. Then lay net only on the bottom. Another strip on top of tube later. All this I lay to one part of mold. From one end I connected resin inflow hose just 10cm inside on the bottom where is a net. Then I put hard smaller tube covered by vacuum film agglutinated with sealing tape along the mold. Then I lay another net strip on the top and folded all ends of laminate correctly around the hard tube, before connected vacuum hose on the other end of mold at the top between peel-ply and net. After I extracted the hard tube from the inside and slightly folded inside all laminate to cover with a top side of mold. Before covering I lay seal around a perimeter and covered with a top mold. Sealed up both ends and tautened all sides of mold together every 50cm. The I vacuumed it and everything looks great for 15 minutes. So, there are no leaking. I didn't put a spiral as a tube is D=75mm and I think the net is enough for resin flow.After 20 minutes infusion I observed resin flow in vacuuming end of mold, but it flows with air bubbles. I tried this 4 times and the result is similar. After demolding there are small bubbles of air on the top of the product. Where is this air from and whats wrong? Thanks! Looks well thought out. If you had a perfectly sealed bag and the resin got to the catch pot that is good. You say you haven't done an infusion before so I think you are worried about seeing air in the vacuum line where it comes out of you molding. That is normal . When you infuse you can watch your resin front look like its boiling and that is fairly normal. But notice as the front travels the area behind it becomes clear. so when the front gets to the vacuum output tube I always let the remainder of my input resin flow until it is almost all used up to kind of aid in flushing out the bubbles at the catchpot. Also when I make a mold I try to have more distance for the resin to flow through the stack at the catchpot end so any bubbles will be cut off of the finished part. Hope this makes sense. Fred
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fgayford	fgayford posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 433, Visits: 1.2K	Jdmleesy (02/02/2014) I will defo do that Fred thank you although it didn't look like it had pierced it there b4 but it was only a tiny leak so I could if missed it i suppose.I'm just prepping the mould up ready to give it another go tomorrow hopefully. Do u guys envelope it aswel or use the pleat method because I don't know if I messed up on the gumtape b4 but I was so carful If you want to see the way I pleat google a guy called John Burns making carbon fiber parts. He is dry, but boy is his pleating method a life saver for me. Fred
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fgayford	fgayford posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 433, Visits: 1.2K	ajb100 (02/02/2014) Have to agree with Fred, the white plastic infusion mesh is a paint to get to form to a mould and the edges punctured the bag. I went for a short time wrapping the edges in masking tape until I started using a different mesh and not had any problems since Just one thing I want to add here. There is nothing wrong with easycomposites flow media mesh. You just need to put a small strip of peelply over every cut before you bag. It only takes seconds and you are sure to have a prefect seal. Why take the chance. Hope this helps. Fred
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justas	justas posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 8, Visits: 65	Thanx Fred, This is one of the best try on pic. Middle next week I'll make some from others to better show brack. Air bubbles coming out are pretty large, from 0.5 to 5 cm! Maybe I should use a spiral along on the bottom from resin and on the top for outcome, how do you think? Actually then will be harder to pull out peel-ply but I am using wire and yacht winch and at the moment there are not problems with that.
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fgayford	fgayford posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 433, Visits: 1.2K	justas (08/02/2014) Thanx Fred, This is one of the best try on pic. Middle next week I'll make some from others to better show brack. Air bubbles coming out are pretty large, from 0.5 to 5 cm! Maybe I should use a spiral along on the bottom from resin and on the top for outcome, how do you think? Actually then will be harder to pull out peel-ply but I am using wire and yacht winch and at the moment there are not problems with that. I think I follow you. I use spiral across the resin feed front of the part and spiral across the vacuum exit of my molds. I am very care full to cover the spiral with a strip of peel ply because you can get a leak there also. In essence I do not allow the vacuum bag to touch a spiral tube or a flow media cut line period! Hope this helps. Fred
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Fasta	Fasta posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 3.5K	I have to ask what you did to seal the mould split/flange so that air can not get in? Fastacraft Facebook page
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justas	justas posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 8, Visits: 65	Yes, spiral can damage vacuum film. Here one of worst attempts Mold opened
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justas	justas posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 8, Visits: 65	To prevent leaking I am using special vacuum sealing type like this. I use it to bond vacuum film to vacuum film or film to mold. Also I am using a specific rubber sealing type between both sides of mold on a flange. Actually now I am making rope 1,5cm wide on a flange of new molds and fill it with liquid silicon so I have reusable sealing type in a right place.
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justas	justas posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 8, Visits: 65	Sorry no ropes but grooves Here is a picture.
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ChrisR	ChrisR posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 363, Visits: 3K	Your application is shouting to me OOA pregreg and bladder pressure tube rather than infusion. How long is the tube you are making? one inlet close to the end may not be enough to ensure full saturation/infusion as you will get a pressure head drop over the length of the part. 15mins may not be enough to get the air out of the system and again depending on the layup you may inherently get dry spots if air is trapped. Try 40mins+ on vac before infusing and do a vac drop test Have you got a dam at the end is the outlet driectly fed off the infusion mesh? You could try a slower mesh or a longer dam at the end.
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