Thin resin

[J.T.Window]

So, has anyone found thin resin to be weaker or less elastic or less durable than thick resin?

[repare-brise]

Jt

What brands of resin, what application, what temperature.......?

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[J.T.Window]

Have you had equal results with the thin and thick versions of your brand of resin? ...in all conditions?
I've been told that the thicker resins have more strength and elasticity - something to do with having more 'glue in the glue.'
What do you think?

[repare-brise]

Thickness of resin is not an indicator of bonding strength. The thickness of the resin can be controlled by various components, on high quality resins these components increase cured elasticity, and resist shrikage during curing(and after). On cheaper resins they are fillers that can cause shrinkage, and bond failure. Using thick resin is counterproductive unless you need high gap filling, dealing with a hot windshield, or you are striving for a perfect match to the refractive index of the glass(certain thickeners aid in approaching the cured resins refractive index to that of the glass, best used in repairs that have a large visable surface area such as a Bulls-Eye). All of the top manufacturors resins surpass the tensile strength of glass by a large margin, some "bargin brands" can be up to 50% weaker than brand name resins. If you want a good test of a resins strenght(without going through the expense and rigors of a lab) there is an inexpensive(and in certaincases fun) way of testing bonding strength(while not exact, it gives a basic understanding of the resins strength).
Make a 1 foot square box with 1 open side out of a substancial material. Purchase some laminated glass squares from a local glass shop(they are cheaper if you buy them pre-cracked) and using WS eurethane bond said piece to the open end of the box(before bonding mark glass on back to show crack after repair). Using your chosen resin, fill the crack(even though it's not a specific drack resin it will fill), cure using your lamp for the time specified by the resin supplier, and let the games begin.

At this point I must say those majic words, this is dangerous and you must consider the risks and take the actions neccesary to protect yourself from danger.

Place the box in a heavy burlap bag(or similar) and from a distance of about 6 feet (this is where the fun begins) drop a heavy object on the glass(a bowling ball or sledge hammer perhaps) wearing gloves carfully remove the box from the bag and observe the glass, note where the repair was done to see if failure was worse in those area's. remove broken glass from box using appropriate caution. You can then repeat the experiment for other resins witha fresh piece of glass.

Be carefull and amuse yourself

[boyd]

J.T.
Have you gone to the hobby store yet?
Yvan ... I'm always amused. You always have great answers and you have a high vocabulary but sometimes I have to roll my eyes. Anyway ...
J.T. I'm no chemist or chemical engineer however, I have used 3 types of resins for over 10 years in TN. My climates are not drastic, rarily below 35 degrees and never over 90. But I can answer your question in laymens terms without conducting an experiment.
To answer your first question about results: yes equal results
No. To all conditions.
Thin resin, for me, is used on small, tight cracks or in cold weather.
It's used here for these reasons: small and tight because it's thinner of course and my medium would take a long time to get to the end.
In cold weather because it moves quicker than the medium. I also cure it slower. Also I never use heat. I think if you use the correct resin you don't need to.
Medium is used at all other times and is my first choice. Yes it is more elastic
and has less shrinkage. I use this at all times unless, as I mentioned earlier, the weather is below say ... 40 degrees.
On a longer crack, which I've done many but turn most down, I use the thin at the end (tightest area), I use it until it starts to move easily, then I use the medium for about 50% fo the crack and then the last 25% I use my pit filler. For 2 reasons in this order. One: less shrinkage in the crack because the thinner it is the more shrinkage you have and two: the thicker it is the more elastic it is and you have more movement in the center and beginning.
That's my thoughts, it's worked for me. It was explained to me my the man that makes the resin where I purchase mine. I'm sure he could have made it sound more difficult by using big words, but sometimes too much info. is unesessary. I don't ask my wife about her previous lovers 20 years ago and I don't ask the guy who makes the resins the chemical names and all that other jazzz .
Good luck.
BOYD

[Delta Kits]

Keep in mind...Different manufacturers' resins have different characteristics. While some brands require multiple viscosities, others don't and have as good or better results.

[boyd]

How many different viscosities (thicknesses) does Delta reccommend?

[Delta Kits]

When using Delta Kits products, you need one viscosity resin only. Depending on which resin you prefer (MagniBond or Premium Bond), the viscosity is either 14-15CPS or 15-20CPS. Once picked, use only that resin on any type of damage.

You still need pit resin to finish off the cap obviously.

[boyd]

That's interesting. Some w/s repair companies offer several resins and tell the people only to use certain resins for certain cracks. I'm glad to know you all don't. I think it's a gimmik to sell more resin (or different kinds).
As I said earlier.... I do the same thing you offer. Two types and a pit filler.

Thanks.
BOYD

Out of curiosity ... how many different resins does Glass Mechanic reccommend? Anybody out there know?

[repare-brise]

Boyd

Officially they reccomend 4, Star resin, bulls eye resin, crack resin and pit filler resin. The additional resins that I use are my choice, and not pushed by GM. You can use only one resin with there system as well (anyone's injector for that matter) but they prefer to sell resins that are not multipurpose. but application specific. I don't feel that any one companies approach is better, but just different. As for selling more resin, they don't, they just sell less of each. And techs don't use any more resin as well, resin usage goes to number of repairs, not number of bottles in your kit. Some people prefer the simplicity of 1 resin for everything(the adjustable wrench) while others prefer having the choice of more application specific resins(a complete set of wrenches). In the end if you are satisfied with your system, you are obtaining resuts that satisfy both you and your customers, then you have the right system for you.

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