Counterfeit thermal paste – GeekTC’s opinion on the Dowsil TC-5888 and what to make of it

About a month ago, I showed in detail that a supposedly original DOWSIL TC-5888 thermal compound from Chinese sources was in fact a fake. My measurements in the laboratory, the chemical analysis and the deviating thermal behavior left no doubt that this product did not come from a regular production facility. The case seems to have spread, as I have now received an email from a long-standing customer of the retailer in question, GeekTC, who referred to two recent statements on Bilibili – a text statement from September 25 and a video that was published on the same day.

The sender of the email, who describes himself as a long-time reader of my site, wanted to know whether GeekTC had contacted me directly in the meantime. He writes that a mere public apology is worth nothing unless you personally answer to the person who uncovered the fraud. Literally: “If they haven’t responded to you in person and directly, they are just doing a double face act and don’t deserve my trust anymore.” A perfectly understandable view, because credibility does not start with a marketing video, but with transparency towards those who are demonstrably affected.

I looked at the two linked posts. The first, a text post on Bilibili, contains a general statement from the dealer. It describes the company as a reseller of hard-to-find B2B products, which are then repackaged for end customers. The retailer states that the offending batch of TC-5888 was purchased from a supplier and only later turned out to be counterfeit. They have informed the affected customers, want to check more closely in future and set up their own laboratory.

I have had the text translated accordingly:

Translation of GeekTC’s statement on Bilibili (September 25, 2025)

Dear friends, thank you for your patience and for your continued interest in GeekTC.

On the evening of September 22, we received a tip from a user about the publication of the foreign testing institution igorsLAB, which expressed doubts in an article about the authenticity of the DOWSIL TC-5888 bottled and distributed by us. We immediately read this article in full and were frankly deeply shocked.

“If you have made a mistake, you have to admit it, and those who deserve to be hit should stand up for it” – with this principle in mind, we launched an internal investigation that very night to find out whether we had indeed made any mistakes, where they lay and how we could correct them.

Since then, we have been working intensively to clarify the matter and the process is still ongoing. Here is an interim report on the current status and the measures taken:

1. Blocking and delisting

As the review and testing will take some time, we have taken all TC-5888 products offered on our platforms off sale as a precautionary measure. The unsold stock has been sealed and set aside to preserve evidence.

2. Preliminary stock check

There are currently 59 filled units (production date April 16, 2024, shelf life 2 years) and one unopened original can (production date April 27, 2024) in stock.

Upon inspection, it became apparent that the color and consistency of the unfilled batch differed slightly, while the filled version appeared somewhat thinner. After random testing on several test systems, the temperature of the bottled batch was 1 to 2 degrees higher than that of the unfilled batch.

3. Comparative tests

We have ordered two new original cans of TC-5888 from an officially authorized first supplier (DOW authorization verified), which are expected to arrive at the end of the month. At the same time, we are in contact with two recognized testing laboratories, SGS and CTI (China Testing & Inspection). Once the goods have arrived, both the sealed remaining stock and the new batch will be submitted together for analysis.

(Note: Due to trade restrictions, the original source of supply is currently unavailable; the previous shipment of 3 kg TC-5888 was from Dongguan Taoxin Electronic Materials Co., Ltd.)

The testing period is estimated at 10 to 15 working days.

4. Customer service and compensation

According to internal tracking, the distribution of TC-5888 supplied by Taoxin started on July 28, 2025.

If the test result confirms that there are quality issues, we will immediately launch a compensation program. All buyers of the affected batch will receive a refund of ten times the purchase amount. The data collection for this has already been completed; this affects a total of 477 sales with a total quantity of around 1.8 kg of material.

Regardless of the test result, we will offer any customer who has purchased our TC-5888 and has doubts about the product quality a free replacement with a new, verifiably original batch from an authorized supplier.

5. Self-criticism and corrective measures

Our internal investigation has revealed significant shortcomings in the traceability of the supply chain and in quality control during filling.

As the TC-5888 is only sold in small quantities and there are procurement difficulties, traceability management was not implemented strictly enough. The incoming goods inspection was also only carried out on a random basis and was not complete.

We have therefore initiated immediate corrective measures:

– Strict traceability of the entire supply chain with complete documentation and legally compliant traceability

– Complete review of all products currently on sale

– Commitment to a complete quality inspection of all future batches with the aim of “zero defects”

This experience has made it clear to us that “he who forges the iron must be strong himself”. Our own inadequacy has led to the incident causing an international stir – we find this shameful and regrettable.

We will do everything in our power to eliminate the negative effects at home and abroad.

We would like to apologize sincerely and with deep regret to all those affected for the uncertainty and inconvenience caused by this incident.

Authenticity and originality of the products are our fundamental promise to every customer. If errors occur, we take full responsibility and are prepared to bear all legal consequences. If it turns out that others have acted unlawfully, we reserve the right to hold those responsible legally accountable.

We would like to thank all users for their continued trust and critical support. At the same time, we would like to expressly express our respect for igorsLAB’s thorough technical analysis and review. It has shown us how much we still have to improve.

As soon as the new test results and complete information are available, we will inform the public immediately.

The subsequent video entitled “GeekTC’s Response to TC-5888 Incident” takes up this point again and presents alleged laboratory results that are supposed to confirm the suspicion. It reads in analogous translation:

“We have found that the affected batch of TC-5888 is significantly different from the latest batches from our regular supplier. After laboratory tests, it has been confirmed that it is a counterfeit product. We apologize to all affected customers and are starting a compensation program. At the same time, we will set up our own laboratory to better test future products.”

At first glance, this sounds like insight and a sense of responsibility. But if you listen more closely, you will notice that it is essentially classic damage limitation. No concrete figures are given on the quantities involved, nor is it clear which independent laboratories are supposed to have carried out these tests. Above all, no direct contact has yet been made with me as the person who made this case public in the first place and provided technical evidence. Since the publication of my article, there has been radio silence.

The mood in the comments under the video is correspondingly tense. Many Chinese users are calling for a comprehensive review of all products still on offer – especially the Honeywell PTM 7950, which originally made GeekTC famous. There are repeated comments to the effect that this apology was only made because a foreign tester had uncovered the fraud. An apt observation, because if the analyses had not been publicly documented, no one would probably have spoken out.

I generally welcome any form of clarification, even if it comes late. Nevertheless, the question remains as to whether GeekTC is actually learning from this incident or simply trying to salvage its image. Setting up its own laboratory is a laudable approach, but as long as there is no external review or transparent test documentation, this announcement remains non-binding. Even a promise of compensation is only credible if it is demonstrably implemented and not just verbally announced.

The case shows once again how necessary independent tests and laboratory analyses are – especially in a market in which counterfeit or inferior thermal pastes can not only jeopardize performance, but in extreme cases also safety. In my laboratory, the paste in question showed clear signs of degradation within a few hours, which normally only occur with liquid metals containing gallium. The fact that something like this was marketed as “TC-5888” is unacceptable in every respect.

I will continue to follow the process and check whether GeekTC actually follows up its announcements with action. The fact is: To date, no one has contacted me or asked for technical details. In my understanding of responsibility, a public apology without direct consequences is not enough. Anyone who seriously wants to win back trust must act transparently, deliver verifiable results and face up to criticism. Anything else remains a mere facade.

The dark business with counterfeit thermal pastes – DOWSIL TC-5888 targeted by clone warriors, including a rather well-made clone-copy