tips and tricks about fiberglassing

[TheCafeKid]

thats a goodtip to know btw dose any one know of any websites that sell f/glass tanks?

www.airtech-streamlining.com

Heres the thing with 'glass tanks tho

One: They are expensive.
Two: they are dangerous
Three: They dont like pump gas, so you'll have to get the inside treated with POR15 or Kreem or the like, and then pray to god you got it right.
Four: they dont "mount right up" You'll need to take EXTENSIVE measurements to see if the design you like will fit the shoulders of our fairly wide framed bikes (compared to the bikes that are usually used for cafe projects, and what most of the tanks are made for) and down the "tunnel" Then you have to do some fabrication of brackets to get it to mount, and likely use "straps" to hold it on.

Frankly, I found it easier, and more fun to pound your "knee inserts" into a stock tank and modify it yourself. Just my two cents.

[andtex24m]

any quick tips on pounding the knee inserts?

[TheCafeKid]

any quick tips on pounding the knee inserts?

Sure,

Take your tank, and drain it obviously. Remove the petcock as not to damage it during the mod.

Put the tank back on the bike, and sit on the bike, and then decide where your knees usually are. With a sharpie, draw a rough outline of where they fall on one side. Then take the tank back off, and with a peice of tag board or something, make a template of exactly what you want your indents to look like. Then trace that template on to the tank on both sides, so the both match. Dont try to eyeball it, as there are things that will throw your eye, such as the fact that the Suzuki emblems arent equal on both sides.

Once you have your lines the way you like em, use a fairly heavy deadblow or ball peen hammer ( i suggest the deadblow, as it will leave less rough spots to bondo over, unlike the peen) and start about a half inch inside your line along the top of the pattern. Smack it fairly firmly, and run alont the top edge of your pattern, keeping just about that 1/2 inch inside it. You'll get the feel for how much the metal will bend with each blow pretty quickly. When you get to the front of your pattern where it starts to round out, stop, and then move back to the back of the tank but along the bottom of the pattern. Here you'll want to only be about 1/4 inch or so from your line, as the seams in the bottom of the tank make the metal a little stiffer, so it wont want to bend as easily as the top did, so you may have to smack it a little harder as well. Move along the bottom edge there till you are about in the same spot as the top. Then moving from front to back, up and down, start hitting across the middle section of your pattern. Take care here as the metal will bend a little easier. Also, take care not to get one section dramaticly lower than anywhere else, or you will start having problems with the metal pinching, and its a pain to flatten that out once it starts. The back side of the patter should be beaten in fairly shallow, and as you move to the front, start hitting in a radial pattern along where your indents are supposed to curve in front. Keep away from the edge of your line about 1/4 inch here, and let your hits draw the line edge in. You'll see that it pretty much does what you want it to as long as you dont hit right up on the edge. the front section should be deeper than the back, and you can decide how extreme you want them to be, but be aware that the more extreme you go, the more bondo work its going to take to make it transition smoothly. Also on the petcock side, if you beat it in too far, you wont have room for your petcock filter screen....

Once you have both sides beaten in the way you like, you'll need to bust out the body filler and smooth things out, making your transitions smooth. The nice thing about the Deadblow is that it keeps things in the "valley" relatively flat and smooth, so you really only need to skimcoat things there. IN the curves its a bit tougher as the compound curves make spreading the bondo without drawing lines thru it rather tough.

I have some pretty good pics of a couple different tanks ive done if you're interested in seeing...

TCK

[andtex24m]

yeah i wanna see the tanks =)

[beergood]

Hammering your tank is pretty easy, after you swing that first blow (just tell yourself, replacement tanks aren't that expensive).

CafeKid's advice is pretty spot on. If I can make one addition: cut a wood spacer that fits snuggly in between the two front mounts. When I did mine, I didn't do this. I was flying blind, there are a couple of us that have done this and posted about it since. The tunnel in my tank ended up a little narrower than it was before I started. The difference is fractional, but it has made getting the tank on the rubber plugs a lot harder. I think a simple spacer would have prevented it, either that or hammering it on the frame.

Also, and this isn't meant to worry you, but when a buddy of mine did this to his tank, he got a little bossy with the hammer on the bottom edge and cracked his seam. Nothing 5 minutes with a welder didn't fix, and I didn't experience anything close to it, so don't give it any more thought than it's worth.

[skivit]

some info, fuel tanks will always need coated.
polyester- basic resin system
vinylester-Skincoat between polyester and epoxy (no chemical adhesion)
epoxy- postcure needed.

Fuel will always eat into all the above systems, it stays porous thru the fibres.
we are coating the diesel/ water tanks on the boat at work at the moment, 1 layer every night for the week.

Been working with composites for the past 14 years, if you need any info give me a shout

here is what i make at the moment

http://www.zeydon.com/newsdesk/picturegallery.aspx

[drhach]

Just to correct a few misconceptions

One: They are expensive.
Not true. Compare Airtech's prices to what a new OEM tank would cost you.

Two: they are dangerous
Sort of Not true. They are as dangerous as anything that is poorly designed and built. A custom aluminum tank can crack at the seams, leak fuel and light your bike on fire. If a composite tank is built properly, they are as safe as anything.

Three: They dont like pump gas, so you'll have to get the inside treated with POR15 or Kreem or the like, and then pray to god you got it right.

Wrong again. Old style polyester was affected by alcohol in fuel. There are a multitude of resins available that are impervious to alcohol

Four: they don't "mount right up" You'll need to take EXTENSIVE measurements to see if the design you like will fit the shoulders of our fairly wide framed bikes (compared to the bikes that are usually used for cafe projects, and what most of the tanks are made for) and down the "tunnel" Then you have to do some fabrication of brackets to get it to mount, and likely use "straps" to hold it on.

Does any custom tank "mount up". If it is not an exact replica of the tank that came from the bike originally. Don't expect any tank to mount up. How many people post on this forum asking what fits what and get told that they are SOL?

Frankly, I found it easier, and more fun to pound your "knee inserts" into a stock tank and modify it yourself. Just my two cents.

This is a matter of preference and has nothing to do with technicalities.

Composites are safe when handled properly. Composites have their issues, just like steel and Aluminum. The problem arises when people approach composites with a "steel" mindset. Plastic tanks are made and sold everyday that are safe and legal. If you need proof, I'll show you a picture of my DR650 with a plastic IMS tank. Granted it is a different kind of plastic. It is still plastic and it is still safe.

Composite tanks were made in the 70's they were safe then too. Norton made a lot of them back in the day. The biggest problem with composite production is from a manufacturing standpoint. That is why they were dropped, not because of illegality or safety. It is hard to mass produce composites. Manufacturers either went with steel or plastic tanks with some sort of paintable bodywork over over them.

All that aside, a gas tank is a big undertaking. It does have to be done right and you should know what you are doing. It probably is not the best project to learn on.

[TheCafeKid]

Just to correct a few misconceptions



Composites are safe when handled properly. Composites have their issues, just like steel and Aluminum. The problem arises when people approach composites with a "steel" mindset. Plastic tanks are made and sold everyday that are safe and legal. If you need proof, I'll show you a picture of my DR650 with a plastic IMS tank. Granted it is a different kind of plastic. It is still plastic and it is still safe.

Composite tanks were made in the 70's they were safe then too. Norton made a lot of them back in the day. The biggest problem with composite production is from a manufacturing standpoint. That is why they were dropped, not because of illegality or safety. It is hard to mass produce composites. Manufacturers either went with steel or plastic tanks with some sort of paintable bodywork over over them.

All that aside, a gas tank is a big undertaking. It does have to be done right and you should know what you are doing. It probably is not the best project to learn on.

Uhmm I just basicly listed the warnings off AIRTECH's SITE...so if you're calling me wrong, you might want to call them out, yanno, since they do it for a living and stuff...I do believe the original question was asked about thier products.

An "OEM" tank, most of which are no longer available, but there are a couple, can be had for a few hundred bucks. MOST of the tanks I saw that would even come CLOSE to fitting our frames, are in the 4-600 dollar range. Thats not bad, compared with the 1800 bucks it would cost you to get a comparable tank from the Tank Shop in Scottland made of alloy, but still, more than I am going to spend on a cheap cafe project.

Airtech's site simply states that you'll want to have their tanks lined to prevent problems created by pump gas. So you can take that up with them.


As far as "mounting up", very few are told they are SOL...I have actually done alot of work regarding what fits what, and have found quite a few GS tanks that fit other models. The ONLY time you are SOL is trying to fit an "L" tank to a standard model, and to be honest, it could be done with SLIGHT modification. As I said, MOST of the tanks that AIRTECH sells are NOT designed to be used on our wide shouldered bikes. Those that will fit will require a bit of work. That was my point... You WILL have to take EXTENSIVE MEASURMENTS to see if it will fit your bike. Period. Anyone who says otherwise is flat ass lying to you. I dont know about you, but Id rather spend 4-700 bucks ELSEWHERE on the project other than a 'glass tank. I consider myself pretty handy with a hammer and body filler at times, so yes that is my preference. That 700 bucks i could spend on things that COUNT in a true cafe project, yanno, like BRAKES, or SUSPENSION, or the powertrain.....

[drhach]

Uhmm I just basicly listed the warnings off AIRTECH's SITE...so if you're calling me wrong, you might want to call them out, yanno, since they do it for a living and stuff...I do believe the original question was asked about thier products.

An "OEM" tank, most of which are no longer available, but there are a couple, can be had for a few hundred bucks. MOST of the tanks I saw that would even come CLOSE to fitting our frames, are in the 4-600 dollar range. Thats not bad, compared with the 1800 bucks it would cost you to get a comparable tank from the Tank Shop in Scottland made of alloy, but still, more than I am going to spend on a cheap cafe project.

Airtech's site simply states that you'll want to have their tanks lined to prevent problems created by pump gas. So you can take that up with them.


As far as "mounting up", very few are told they are SOL...I have actually done alot of work regarding what fits what, and have found quite a few GS tanks that fit other models. The ONLY time you are SOL is trying to fit an "L" tank to a standard model, and to be honest, it could be done with SLIGHT modification. As I said, MOST of the tanks that AIRTECH sells are NOT designed to be used on our wide shouldered bikes. Those that will fit will require a bit of work. That was my point... You WILL have to take EXTENSIVE MEASURMENTS to see if it will fit your bike. Period. Anyone who says otherwise is flat ass lying to you. I dont know about you, but Id rather spend 4-700 bucks ELSEWHERE on the project other than a 'glass tank. I consider myself pretty handy with a hammer and body filler at times, so yes that is my preference. That 700 bucks i could spend on things that COUNT in a true cafe project, yanno, like BRAKES, or SUSPENSION, or the powertrain.....

Sorry that I ruffled your feathers. I didn't mean to do that. Regarding Airtech, I part ways with them on a couple of different fronts. Obviously they are trying to avoid getting sued and they also don't want some crackpot demanding a refund after he bought a generic tank and did not understand why it didn't fit his bike. Also, regarding fuel. Again, if the tank is properly made, it is impervious to today's fuels. I can't speak for airtech and what materials they choose to use. If they use products that do not meet today's standards that is their concern. Perhaps copying and pasting information that you do not know to be accurate isn't the best approach though. I've done a fair amount if research in this area and I can cite many credible sources that support my claims. I'm not trying to get in to a ****ing match, I just don't see much value in giving advice about things that i am not somewhat versed in. I am also quick to admit that I am wrong when there is evidence that that is the case. Anyway, I think the OP was asking about pointers regarding making a fiberglass tank not about Airtech specifically. At least that's what I gathered from the first post.

Regarding buying a generic tank. I don't disagree with you. It probably won't fit. The thing is, this is true for pretty much any generic part that you buy, regardless of what it is made of. This is not unique to fiberglass.

Lastly, I would love to know your findings regarding different tanks that fit. I myself have a 1978 GS1000. To my knowledge on the GS1000 only tanks from 1978 to 1980 GS1000's fit that particular bike I have read many posts from individuals asking specific questions about fitment and I have never seen anyone give any kind of decent information. That's not to say that it hasn't been given. I may have missed it. But things tend to become common knowledge around here after a while. I'm not aware of any knowledge base regarding fitment of tanks. So, that is the basis of that claim. It's entirely possible that I'm wrong (it happens a lot, just ask my wife). If so, sorry for the misunderstanding.

[drhach]

some info, fuel tanks will always need coated.
polyester- basic resin system
vinylester-Skincoat between polyester and epoxy (no chemical adhesion)
epoxy- postcure needed.

Fuel will always eat into all the above systems, it stays porous thru the fibres.
we are coating the diesel/ water tanks on the boat at work at the moment, 1 layer every night for the week.

Been working with composites for the past 14 years, if you need any info give me a shout

here is what i make at the moment
http://www.zeydon.com/newsdesk/picturegallery.aspx

That's a great looking Boat

[TheCafeKid]

Sorry that I ruffled your feathers. I didn't mean to do that. Regarding Airtech, I part ways with them on a couple of different fronts. Obviously they are trying to avoid getting sued and they also don't want some crackpot demanding a refund after he bought a generic tank and did not understand why it didn't fit his bike. Also, regarding fuel. Again, if the tank is properly made, it is impervious to today's fuels. I can't speak for airtech and what materials they choose to use. If they use products that do not meet today's standards that is their concern. Perhaps copying and pasting information that you do not know to be accurate isn't the best approach though. I've done a fair amount if research in this area and I can cite many credible sources that support my claims. I'm not trying to get in to a ****ing match, I just don't see much value in giving advice about things that i am not somewhat versed in. I am also quick to admit that I am wrong when there is evidence that that is the case. Anyway, I think the OP was asking about pointers regarding making a fiberglass tank not about Airtech specifically. At least that's what I gathered from the first post.

Regarding buying a generic tank. I don't disagree with you. It probably won't fit. The thing is, this is true for pretty much any generic part that you buy, regardless of what it is made of. This is not unique to fiberglass.

Lastly, I would love to know your findings regarding different tanks that fit. I myself have a 1978 GS1000. To my knowledge on the GS1000 only tanks from 1978 to 1980 GS1000's fit that particular bike I have read many posts from individuals asking specific questions about fitment and I have never seen anyone give any kind of decent information. That's not to say that it hasn't been given. I may have missed it. But things tend to become common knowledge around here after a while. I'm not aware of any knowledge base regarding fitment of tanks. So, that is the basis of that claim. It's entirely possible that I'm wrong (it happens a lot, just ask my wife). If so, sorry for the misunderstanding.

Ive read, but never tried with a 1000, as ive never had one on hand, that a 79-81 850 tank will work. I have also SEEN a 77-79 750 tank ON a 1000. Now, i didnt get to examine whether or not he had to use and rear mount extensions, but to MY knowlege, MOST of the single, horizontal bolt rear, and neck plate front mounted tanks will interchange. I have PERSONALLY drawn measurements from an early 80s 550 ( 81 L model ) and an 79 or 80 850L model ( i cant be for SURE which year it was, but it was before they increased the size of the L tank) and the 850 tank will fit the 550. Now, I once tried to afix a 77-79 750 tank to an 80-82 750 frame. THAT wont work. the shoulders on the frame are either too wide, or the tunnel is too narrow, however you chose to look at it. It MAY fit a 1000, if you can find someone to take certain important measurements, which id be happy to give you, you can find out. I do know that the 80-82 750 tank and the 80-81 1100 tank will interchange, because, well, they're one and the same...lol

As to the above: I maybe mistook the question. I thought he SPECIFICALLY asked as to Airtech's tanks. I was simply giving the information that i gleaned from their site. That is all on that. I have limited experience with 'glass, only in what ive made myself, and what ive learned from a good friend that does glass work on jet boats. We have not even discussed the possibility of making a tank, as it would likely be very cost prohibitive unless someone REQUESTED and had designs for a specific tank. To be honest, im not sure how Airtech stays in business, except that they probably make MOST of their money off of modern body and race pannels.